861319557 has 24 divisors (see below), whose sum is σ = 1424244224. Its totient is φ = 491357664.

The previous prime is 861319549. The next prime is 861319567. The reversal of 861319557 is 755913168.

It is a happy number.

861319557 is a `hidden beast` number, since 8 + 61 + 31 + 9 + 557 = 666.

861319557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 861319557 - 2³ = 861319549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861319567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27468 + ... + 49770.

Almost surely, 2^861319557 is an apocalyptic number.

It is an amenable number.

861319557 is a deficient number, since it is larger than the sum of its proper divisors (562924667).

861319557 is a wasteful number, since it uses less digits than its factorization.

861319557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22929 (or 22926 counting only the distinct ones).

The product of its digits is 226800, while the sum is 45.

The square root of 861319557 is about 29348.2462338042. The cubic root of 861319557 is about 951.4546715141.

The spelling of 861319557 in words is "eight hundred sixty-one million, three hundred nineteen thousand, five hundred fifty-seven".