861957657 has 36 divisors (see below), whose sum is σ = 1376401572. Its totient is φ = 519393600.

The previous prime is 861957643. The next prime is 861957673. The reversal of 861957657 is 756759168.

861957657 is a `hidden beast` number, since 8 + 6 + 19 + 576 + 57 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 185749641 + 676208016 = 13629^2 + 26004^2 .

It is not a de Polignac number, because 861957657 - 2¹⁴ = 861941273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (861950657) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 194923 + ... + 199295.

It is an arithmetic number, because the mean of its divisors is an integer number (38233377).

Almost surely, 2^861957657 is an apocalyptic number.

It is an amenable number.

861957657 is a deficient number, since it is larger than the sum of its proper divisors (514443915).

861957657 is a wasteful number, since it uses less digits than its factorization.

861957657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4582 (or 4568 counting only the distinct ones).

The product of its digits is 3175200, while the sum is 54.

The square root of 861957657 is about 29359.1153987991. The cubic root of 861957657 is about 951.6895720825.

The spelling of 861957657 in words is "eight hundred sixty-one million, nine hundred fifty-seven thousand, six hundred fifty-seven".