161156556 has 72 divisors (see below), whose sum is σ = 467812800. Its totient is φ = 46262880.

The previous prime is 161156543. The next prime is 161156557. The reversal of 161156556 is 655651161.

161156556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×161156556² = 51942871083562272, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 161156556.

It is not an unprimeable number, because it can be changed into a prime (161156557) 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, 3186 + ... + 18233.

It is an arithmetic number, because the mean of its divisors is an integer number (6497400).

Almost surely, 2^161156556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161156556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (233906400).

161156556 is an abundant number, since it is smaller than the sum of its proper divisors (306656244).

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

161156556 is a wasteful number, since it uses less digits than its factorization.

161156556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21459 (or 21454 counting only the distinct ones).

The product of its digits is 27000, while the sum is 36.

The square root of 161156556 is about 12694.7452120946. The cubic root of 161156556 is about 544.1884574490.

The spelling of 161156556 in words is "one hundred sixty-one million, one hundred fifty-six thousand, five hundred fifty-six".