139181957 has 2 divisors, whose sum is σ = 139181958. Its totient is φ = 139181956.

The previous prime is 139181923. The next prime is 139181983. The reversal of 139181957 is 759181931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 139098436 + 83521 = 11794^2 + 289^2 .

It is a cyclic number.

It is not a de Polignac number, because 139181957 - 2¹⁶ = 139116421 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139181557) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69590978 + 69590979.

It is an arithmetic number, because the mean of its divisors is an integer number (69590979).

Almost surely, 2^139181957 is an apocalyptic number.

It is an amenable number.

139181957 is a deficient number, since it is larger than the sum of its proper divisors (1).

139181957 is an equidigital number, since it uses as much as digits as its factorization.

139181957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 44.

The square root of 139181957 is about 11797.5402944851. The cubic root of 139181957 is about 518.2360807283.

The spelling of 139181957 in words is "one hundred thirty-nine million, one hundred eighty-one thousand, nine hundred fifty-seven".