161616220 has 24 divisors (see below), whose sum is σ = 339991344. Its totient is φ = 64532736.

The previous prime is 161616211. The next prime is 161616269. The reversal of 161616220 is 22616161.

It is a super-2 number, since 2×161616220² = 52239605134176800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5047 + ... + 18673.

It is an arithmetic number, because the mean of its divisors is an integer number (14166306).

Almost surely, 2^161616220 is an apocalyptic number.

161616220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161616220 is an abundant number, since it is smaller than the sum of its proper divisors (178375124).

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

161616220 is a wasteful number, since it uses less digits than its factorization.

161616220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14229 (or 14227 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 161616220 is about 12712.8368195301. The cubic root of 161616220 is about 544.7053593538.

The spelling of 161616220 in words is "one hundred sixty-one million, six hundred sixteen thousand, two hundred twenty".