161566554 has 16 divisors (see below), whose sum is σ = 323333280. Its totient is φ = 53822160.

The previous prime is 161566553. The next prime is 161566577. The reversal of 161566554 is 455665161.

161566554 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 2×161566554² = 52207502742869832, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161566553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3432 + ... + 18300.

It is an arithmetic number, because the mean of its divisors is an integer number (20208330).

Almost surely, 2^161566554 is an apocalyptic number.

161566554 is an abundant number, since it is smaller than the sum of its proper divisors (161766726).

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

161566554 is a wasteful number, since it uses less digits than its factorization.

161566554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16685.

The product of its digits is 108000, while the sum is 39.

The square root of 161566554 is about 12710.8832895279. The cubic root of 161566554 is about 544.6495561510.

The spelling of 161566554 in words is "one hundred sixty-one million, five hundred sixty-six thousand, five hundred fifty-four".