161921952 has 144 divisors (see below), whose sum is σ = 490613760. Its totient is φ = 50512896.

The previous prime is 161921951. The next prime is 161921987. The reversal of 161921952 is 259129161.

161921952 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (161921951) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 694828 + ... + 695060.

It is an arithmetic number, because the mean of its divisors is an integer number (3407040).

Almost surely, 2^161921952 is an apocalyptic number.

161921952 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 161921952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245306880).

161921952 is an abundant number, since it is smaller than the sum of its proper divisors (328691808).

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

161921952 is a wasteful number, since it uses less digits than its factorization.

161921952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395 (or 384 counting only the distinct ones).

The product of its digits is 9720, while the sum is 36.

The square root of 161921952 is about 12724.8556769812. The cubic root of 161921952 is about 545.0486189547.

The spelling of 161921952 in words is "one hundred sixty-one million, nine hundred twenty-one thousand, nine hundred fifty-two".