139565961 has 24 divisors (see below), whose sum is σ = 208932360. Its totient is φ = 89703936.

The previous prime is 139565953. The next prime is 139566041. The reversal of 139565961 is 169565931.

139565961 is a `hidden beast` number, since 1 + 3 + 9 + 56 + 596 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4076361 + 135489600 = 2019^2 + 11640^2 .

It is not a de Polignac number, because 139565961 - 2³ = 139565953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (139565861) 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, 35775 + ... + 39483.

It is an arithmetic number, because the mean of its divisors is an integer number (8705515).

Almost surely, 2^139565961 is an apocalyptic number.

It is an amenable number.

139565961 is a deficient number, since it is larger than the sum of its proper divisors (69366399).

139565961 is a wasteful number, since it uses less digits than its factorization.

139565961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3865 (or 3862 counting only the distinct ones).

The product of its digits is 218700, while the sum is 45.

The square root of 139565961 is about 11813.8038328051. The cubic root of 139565961 is about 518.7122487455.

The spelling of 139565961 in words is "one hundred thirty-nine million, five hundred sixty-five thousand, nine hundred sixty-one".