161331072 has 128 divisors (see below), whose sum is σ = 500567040. Its totient is φ = 45078528.

The previous prime is 161331067. The next prime is 161331077. The reversal of 161331072 is 270133161.

161331072 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (161331067) and next prime (161331077).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161331077) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125698 + ... + 126974.

It is an arithmetic number, because the mean of its divisors is an integer number (3910680).

Almost surely, 2^161331072 is an apocalyptic number.

161331072 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161331072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250283520).

161331072 is an abundant number, since it is smaller than the sum of its proper divisors (339235968).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161331072 is a wasteful number, since it uses less digits than its factorization.

161331072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1348 (or 1336 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 161331072 is about 12701.6169049456. The cubic root of 161331072 is about 544.3848199903.

It can be divided in two parts, 16133 and 1072, that added together give a triangular number (17205 = T₁₈₅).

The spelling of 161331072 in words is "one hundred sixty-one million, three hundred thirty-one thousand, seventy-two".