137978657 has 2 divisors, whose sum is σ = 137978658. Its totient is φ = 137978656.

The previous prime is 137978629. The next prime is 137978671. The reversal of 137978657 is 756879731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137921536 + 57121 = 11744^2 + 239^2 .

It is an emirp because it is prime and its reverse (756879731) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137978657 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 137978599 and 137978608.

It is not a weakly prime, because it can be changed into another prime (137978677) 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, 68989328 + 68989329.

It is an arithmetic number, because the mean of its divisors is an integer number (68989329).

Almost surely, 2^137978657 is an apocalyptic number.

It is an amenable number.

137978657 is a deficient number, since it is larger than the sum of its proper divisors (1).

137978657 is an equidigital number, since it uses as much as digits as its factorization.

137978657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2222640, while the sum is 53.

The square root of 137978657 is about 11746.4316709373. The cubic root of 137978657 is about 516.7382830082.

The spelling of 137978657 in words is "one hundred thirty-seven million, nine hundred seventy-eight thousand, six hundred fifty-seven".