161087820 has 48 divisors (see below), whose sum is σ = 452755968. Its totient is φ = 42793920.

The previous prime is 161087819. The next prime is 161087851. The reversal of 161087820 is 28780161.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11307 + ... + 21213.

It is an arithmetic number, because the mean of its divisors is an integer number (9432416).

Almost surely, 2^161087820 is an apocalyptic number.

161087820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161087820 is an abundant number, since it is smaller than the sum of its proper divisors (291668148).

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

161087820 is a wasteful number, since it uses less digits than its factorization.

161087820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10190 (or 10188 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 161087820 is about 12692.0376614632. The cubic root of 161087820 is about 544.1110779161. Note that the first 3 decimals are identical.

The spelling of 161087820 in words is "one hundred sixty-one million, eighty-seven thousand, eight hundred twenty".