138900961 has 2 divisors, whose sum is σ = 138900962. Its totient is φ = 138900960.

The previous prime is 138900947. The next prime is 138900967. The reversal of 138900961 is 169009831.

138900961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75603025 + 63297936 = 8695^2 + 7956^2 .

It is a cyclic number.

It is not a de Polignac number, because 138900961 - 2⁷ = 138900833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138900961.

It is not a weakly prime, because it can be changed into another prime (138900967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69450480 + 69450481.

It is an arithmetic number, because the mean of its divisors is an integer number (69450481).

Almost surely, 2^138900961 is an apocalyptic number.

It is an amenable number.

138900961 is a deficient number, since it is larger than the sum of its proper divisors (1).

138900961 is an equidigital number, since it uses as much as digits as its factorization.

138900961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 138900961 is about 11785.6251849446. The cubic root of 138900961 is about 517.8870882334.

The spelling of 138900961 in words is "one hundred thirty-eight million, nine hundred thousand, nine hundred sixty-one".