2157688909000 has 128 divisors (see below), whose sum is σ = 5347096765920. Its totient is φ = 812138496000.

The previous prime is 2157688908971. The next prime is 2157688909027. The reversal of 2157688909000 is 9098867512.

It can be written as a sum of positive squares in 16 ways, for example, as 1026456712164 + 1131232196836 = 1013142^2 + 1063594^2 .

It is a super-2 number, since 2×2157688909000² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108739080 + ... + 108758920.

Almost surely, 2^{2157688909000} is an apocalyptic number.

2157688909000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2157688909000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2673548382960).

2157688909000 is an abundant number, since it is smaller than the sum of its proper divisors (3189407856920).

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

2157688909000 is a wasteful number, since it uses less digits than its factorization.

2157688909000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26276 (or 26262 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 55.

The spelling of 2157688909000 in words is "two trillion, one hundred fifty-seven billion, six hundred eighty-eight million, nine hundred nine thousand".