861608564 has 12 divisors (see below), whose sum is σ = 1508372544. Its totient is φ = 430644984.

The previous prime is 861608537. The next prime is 861608593. The reversal of 861608564 is 465806168.

It is a congruent number.

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, 27212 + ... + 49635.

It is an arithmetic number, because the mean of its divisors is an integer number (125697712).

Almost surely, 2^861608564 is an apocalyptic number.

It is an amenable number.

861608564 is a deficient number, since it is larger than the sum of its proper divisors (646763980).

861608564 is a wasteful number, since it uses less digits than its factorization.

861608564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79654 (or 79652 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 44.

The square root of 861608564 is about 29353.1695733187. The cubic root of 861608564 is about 951.5610765870.

The spelling of 861608564 in words is "eight hundred sixty-one million, six hundred eight thousand, five hundred sixty-four".