161578249272 has 576 divisors, whose sum is σ = 517621104000. Its totient is φ = 45414673920.

The previous prime is 161578249271. The next prime is 161578249291. The reversal of 161578249272 is 272942875161.

161578249272 is a `hidden beast` number, since 1 + 6 + 1 + 5 + 7 + 82 + 492 + 72 = 666.

It is a super-2 number, since 2×161578249272² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161578249271) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1162433379 + ... + 1162433517.

It is an arithmetic number, because the mean of its divisors is an integer number (898647750).

Almost surely, 2^161578249272 is an apocalyptic number.

161578249272 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 161578249272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258810552000).

161578249272 is an abundant number, since it is smaller than the sum of its proper divisors (356042854728).

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

161578249272 is a wasteful number, since it uses less digits than its factorization.

161578249272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352 (or 334 counting only the distinct ones).

The product of its digits is 3386880, while the sum is 54.

The spelling of 161578249272 in words is "one hundred sixty-one billion, five hundred seventy-eight million, two hundred forty-nine thousand, two hundred seventy-two".