137186921 has 2 divisors, whose sum is σ = 137186922. Its totient is φ = 137186920.

The previous prime is 137186893. The next prime is 137186939. The reversal of 137186921 is 129681731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134815321 + 2371600 = 11611^2 + 1540^2 .

It is a cyclic number.

It is not a de Polignac number, because 137186921 - 2¹⁰ = 137185897 is a prime.

It is not a weakly prime, because it can be changed into another prime (137186221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68593460 + 68593461.

It is an arithmetic number, because the mean of its divisors is an integer number (68593461).

Almost surely, 2^137186921 is an apocalyptic number.

It is an amenable number.

137186921 is a deficient number, since it is larger than the sum of its proper divisors (1).

137186921 is an equidigital number, since it uses as much as digits as its factorization.

137186921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 38.

The square root of 137186921 is about 11712.6820583503. The cubic root of 137186921 is about 515.7480203610.

The spelling of 137186921 in words is "one hundred thirty-seven million, one hundred eighty-six thousand, nine hundred twenty-one".