861257560 has 16 divisors (see below), whose sum is σ = 1937829600. Its totient is φ = 344503008.

The previous prime is 861257557. The next prime is 861257561. The reversal of 861257560 is 65752168.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 21531439 = 861257560 / (8 + 6 + 1 + 2 + 5 + 7 + 5 + 6 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861257561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10765680 + ... + 10765759.

It is an arithmetic number, because the mean of its divisors is an integer number (121114350).

Almost surely, 2^861257560 is an apocalyptic number.

It is an amenable number.

861257560 is an abundant number, since it is smaller than the sum of its proper divisors (1076572040).

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

861257560 is a wasteful number, since it uses less digits than its factorization.

861257560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21531450 (or 21531446 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 861257560 is about 29347.1899847328. The cubic root of 861257560 is about 951.4318426852.

The spelling of 861257560 in words is "eight hundred sixty-one million, two hundred fifty-seven thousand, five hundred sixty".