138904457 has 2 divisors, whose sum is σ = 138904458. Its totient is φ = 138904456.

The previous prime is 138904453. The next prime is 138904517. The reversal of 138904457 is 754409831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135932281 + 2972176 = 11659^2 + 1724^2 .

It is a cyclic number.

It is not a de Polignac number, because 138904457 - 2² = 138904453 is a prime.

It is not a weakly prime, because it can be changed into another prime (138904453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69452228 + 69452229.

It is an arithmetic number, because the mean of its divisors is an integer number (69452229).

Almost surely, 2^138904457 is an apocalyptic number.

It is an amenable number.

138904457 is a deficient number, since it is larger than the sum of its proper divisors (1).

138904457 is an equidigital number, since it uses as much as digits as its factorization.

138904457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 138904457 is about 11785.7735002841. The cubic root of 138904457 is about 517.8914330991.

The spelling of 138904457 in words is "one hundred thirty-eight million, nine hundred four thousand, four hundred fifty-seven".