136807921 has 2 divisors, whose sum is σ = 136807922. Its totient is φ = 136807920.

The previous prime is 136807901. The next prime is 136807943. The reversal of 136807921 is 129708631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113188321 + 23619600 = 10639^2 + 4860^2 .

It is a cyclic number.

It is not a de Polignac number, because 136807921 - 2⁵ = 136807889 is a prime.

It is not a weakly prime, because it can be changed into another prime (136807901) 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, 68403960 + 68403961.

It is an arithmetic number, because the mean of its divisors is an integer number (68403961).

Almost surely, 2^136807921 is an apocalyptic number.

It is an amenable number.

136807921 is a deficient number, since it is larger than the sum of its proper divisors (1).

136807921 is an equidigital number, since it uses as much as digits as its factorization.

136807921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 136807921 is about 11696.4918244746. The cubic root of 136807921 is about 515.2726378706.

The spelling of 136807921 in words is "one hundred thirty-six million, eight hundred seven thousand, nine hundred twenty-one".