861581608 has 16 divisors (see below), whose sum is σ = 1629763380. Its totient is φ = 426978048.

The previous prime is 861581599. The next prime is 861581627. The reversal of 861581608 is 806185168.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 575904004 + 285677604 = 23998^2 + 16902^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 475635 + ... + 477442.

Almost surely, 2^861581608 is an apocalyptic number.

It is an amenable number.

861581608 is a deficient number, since it is larger than the sum of its proper divisors (768181772).

861581608 is a wasteful number, since it uses less digits than its factorization.

861581608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 953196 (or 953192 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 43.

The square root of 861581608 is about 29352.7104029594. The cubic root of 861581608 is about 951.5511530754.

The spelling of 861581608 in words is "eight hundred sixty-one million, five hundred eighty-one thousand, six hundred eight".