161220020120 has 64 divisors (see below), whose sum is σ = 366556596480. Its totient is φ = 63811789696.

The previous prime is 161220019999. The next prime is 161220020153. The reversal of 161220020120 is 21020022161.

It is a congruent 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, 3775127 + ... + 3817593.

It is an arithmetic number, because the mean of its divisors is an integer number (5727446820).

Almost surely, 2^161220020120 is an apocalyptic number.

161220020120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161220020120 is an abundant number, since it is smaller than the sum of its proper divisors (205336576360).

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

161220020120 is a wasteful number, since it uses less digits than its factorization.

161220020120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43472 (or 43468 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 161220020120 its reverse (21020022161), we get a palindrome (182240042281).

The spelling of 161220020120 in words is "one hundred sixty-one billion, two hundred twenty million, twenty thousand, one hundred twenty".