139855813 has 2 divisors, whose sum is σ = 139855814. Its totient is φ = 139855812.

The previous prime is 139855799. The next prime is 139855841. The reversal of 139855813 is 318558931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129914404 + 9941409 = 11398^2 + 3153^2 .

It is a cyclic number.

It is not a de Polignac number, because 139855813 - 2²⁵ = 106301381 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 139855813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139855843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69927906 + 69927907.

It is an arithmetic number, because the mean of its divisors is an integer number (69927907).

Almost surely, 2^139855813 is an apocalyptic number.

It is an amenable number.

139855813 is a deficient number, since it is larger than the sum of its proper divisors (1).

139855813 is an equidigital number, since it uses as much as digits as its factorization.

139855813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 43.

The square root of 139855813 is about 11826.0649837552. The cubic root of 139855813 is about 519.0710893943.

The spelling of 139855813 in words is "one hundred thirty-nine million, eight hundred fifty-five thousand, eight hundred thirteen".