161566100 has 18 divisors (see below), whose sum is σ = 350598654. Its totient is φ = 64626400.

The previous prime is 161566091. The next prime is 161566121. The reversal of 161566100 is 1665161.

It can be written as a sum of positive squares in 3 ways, for example, as 11062276 + 150503824 = 3326^2 + 12268^2 .

It is a super-2 number, since 2×161566100² = 52207209338420000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161566100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 807731 + ... + 807930.

It is an arithmetic number, because the mean of its divisors is an integer number (19477703).

Almost surely, 2^161566100 is an apocalyptic number.

161566100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161566100 is an abundant number, since it is smaller than the sum of its proper divisors (189032554).

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

161566100 is a wasteful number, since it uses less digits than its factorization.

161566100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615675 (or 1615668 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 161566100 is about 12710.8654308037. The cubic root of 161566100 is about 544.6490459977.

The spelling of 161566100 in words is "one hundred sixty-one million, five hundred sixty-six thousand, one hundred".