3157203721 has 27 divisors (see below), whose sum is σ = 3850321671. Its totient is φ = 2581097904.

The previous prime is 3157203703. The next prime is 3157203727. The reversal of 3157203721 is 1273027513.

The square root of 3157203721 is 56189.

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

3157203721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 2317363321 + 839840400 = 48139^2 + 28980^2 .

It is not a de Polignac number, because 3157203721 - 2⁷ = 3157203593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3157203727) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9046255 + ... + 9046603.

Almost surely, 2^3157203721 is an apocalyptic number.

3157203721 is the 56189-th square number.

3157203721 is the 28095-th centered octagonal number.

It is an amenable number.

3157203721 is a deficient number, since it is larger than the sum of its proper divisors (693117950).

3157203721 is an frugal number, since it uses more digits than its factorization.

3157203721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758 (or 379 counting only the distinct ones).

The product of its (nonzero) digits is 8820, while the sum is 31.

The cubic root of 3157203721 is about 1467.0138093980.

The spelling of 3157203721 in words is "three billion, one hundred fifty-seven million, two hundred three thousand, seven hundred twenty-one".