2157172506 has 32 divisors (see below), whose sum is σ = 4809168000. Its totient is φ = 716739840.

The previous prime is 2157172487. The next prime is 2157172519. The reversal of 2157172506 is 6052717512.

2157172506 is a `hidden beast` number, since 2 + 15 + 71 + 72 + 506 = 666.

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, 47431 + ... + 81018.

It is an arithmetic number, because the mean of its divisors is an integer number (150286500).

Almost surely, 2^2157172506 is an apocalyptic number.

2157172506 is an abundant number, since it is smaller than the sum of its proper divisors (2651995494).

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

2157172506 is a wasteful number, since it uses less digits than its factorization.

2157172506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128771 (or 128765 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The square root of 2157172506 is about 46445.3712010142. The cubic root of 2157172506 is about 1292.0965259510.

The spelling of 2157172506 in words is "two billion, one hundred fifty-seven million, one hundred seventy-two thousand, five hundred six".