2157138728640 has 1008 divisors, whose sum is σ = 8936846410752. Its totient is φ = 475810578432.

The previous prime is 2157138728627. The next prime is 2157138728669. The reversal of 2157138728640 is 468278317512.

2157138728640 is a `hidden beast` number, since 2 + 1 + 571 + 3 + 8 + 7 + 2 + 8 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1008).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 663121254 + ... + 663124506.

Almost surely, 2^{2157138728640} is an apocalyptic number.

2157138728640 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 2157138728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4468423205376).

2157138728640 is an abundant number, since it is smaller than the sum of its proper divisors (6779707682112).

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

2157138728640 is a wasteful number, since it uses less digits than its factorization.

2157138728640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3454 (or 3434 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 54.

The spelling of 2157138728640 in words is "two trillion, one hundred fifty-seven billion, one hundred thirty-eight million, seven hundred twenty-eight thousand, six hundred forty".