161286972 has 96 divisors (see below), whose sum is σ = 493946880. Its totient is φ = 39683520.

The previous prime is 161286967. The next prime is 161286977. The reversal of 161286972 is 279682161.

161286972 is digitally balanced in base 2, because in such base 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 (161286967) and next prime (161286977).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161286977) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12963 + ... + 22149.

It is an arithmetic number, because the mean of its divisors is an integer number (5145280).

Almost surely, 2^161286972 is an apocalyptic number.

161286972 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 161286972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (246973440).

161286972 is an abundant number, since it is smaller than the sum of its proper divisors (332659908).

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

161286972 is a wasteful number, since it uses less digits than its factorization.

161286972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9231 (or 9229 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 161286972 is about 12699.8807868421. The cubic root of 161286972 is about 544.3352127694.

The spelling of 161286972 in words is "one hundred sixty-one million, two hundred eighty-six thousand, nine hundred seventy-two".