161604220 has 24 divisors (see below), whose sum is σ = 341965008. Its totient is φ = 64147200.

The previous prime is 161604199. The next prime is 161604239. The reversal of 161604220 is 22406161.

161604220 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 2×161604220² = 52231847843616800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161604191 and 161604200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28221 + ... + 33460.

It is an arithmetic number, because the mean of its divisors is an integer number (14248542).

Almost surely, 2^161604220 is an apocalyptic number.

161604220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161604220 is an abundant number, since it is smaller than the sum of its proper divisors (180360788).

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

161604220 is a wasteful number, since it uses less digits than its factorization.

161604220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61821 (or 61819 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 161604220 is about 12712.3648468725. The cubic root of 161604220 is about 544.6918775673.

The spelling of 161604220 in words is "one hundred sixty-one million, six hundred four thousand, two hundred twenty".