139861957 has 2 divisors, whose sum is σ = 139861958. Its totient is φ = 139861956.

The previous prime is 139861951. The next prime is 139861993. The reversal of 139861957 is 759168931.

139861957 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 112550881 + 27311076 = 10609^2 + 5226^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139861957 is a prime.

It is a super-2 number, since 2×139861957² = 39122734031739698, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 139861957.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139861951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69930978 + 69930979.

It is an arithmetic number, because the mean of its divisors is an integer number (69930979).

Almost surely, 2^139861957 is an apocalyptic number.

It is an amenable number.

139861957 is a deficient number, since it is larger than the sum of its proper divisors (1).

139861957 is an equidigital number, since it uses as much as digits as its factorization.

139861957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 408240, while the sum is 49.

The square root of 139861957 is about 11826.3247460908. The cubic root of 139861957 is about 519.0786903799.

The spelling of 139861957 in words is "one hundred thirty-nine million, eight hundred sixty-one thousand, nine hundred fifty-seven".