136431521 has 2 divisors, whose sum is σ = 136431522. Its totient is φ = 136431520.

The previous prime is 136431509. The next prime is 136431569. The reversal of 136431521 is 125134631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99221521 + 37210000 = 9961^2 + 6100^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-136431521 is a prime.

It is a super-2 number, since 2×136431521² = 37227119844746882, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (136431221) 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, 68215760 + 68215761.

It is an arithmetic number, because the mean of its divisors is an integer number (68215761).

Almost surely, 2^136431521 is an apocalyptic number.

It is an amenable number.

136431521 is a deficient number, since it is larger than the sum of its proper divisors (1).

136431521 is an equidigital number, since it uses as much as digits as its factorization.

136431521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 26.

The square root of 136431521 is about 11680.3904472411. The cubic root of 136431521 is about 514.7996468276.

The spelling of 136431521 in words is "one hundred thirty-six million, four hundred thirty-one thousand, five hundred twenty-one".