161665376152900 has 81 divisors (see below), whose sum is σ = 355114644431421. Its totient is φ = 63882869770080.

The previous prime is 161665376152751. The next prime is 161665376152921. The reversal of 161665376152900 is 9251673566161.

The square root of 161665376152900 is 12714770.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 58199535415044 + 103465840737856 = 7628862^2 + 10171816^2 .

It is a super-2 number, since 2×161665376152900² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 10553251441 + ... + 10553266759.

Almost surely, 2^{161665376152900} is an apocalyptic number.

161665376152900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161665376152900 is the 12714770-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161665376152900

161665376152900 is an abundant number, since it is smaller than the sum of its proper divisors (193449268278521).

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

161665376152900 is an frugal number, since it uses more digits than its factorization.

161665376152900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30818 (or 15409 counting only the distinct ones).

The product of its (nonzero) digits is 12247200, while the sum is 58.

The spelling of 161665376152900 in words is "one hundred sixty-one trillion, six hundred sixty-five billion, three hundred seventy-six million, one hundred fifty-two thousand, nine hundred".