136721831 has 2 divisors, whose sum is σ = 136721832. Its totient is φ = 136721830.

The previous prime is 136721759. The next prime is 136721909. The reversal of 136721831 is 138127631.

It is a weak prime.

It is an emirp because it is prime and its reverse (138127631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 136721831 - 2¹⁰ = 136720807 is a prime.

It is a super-2 number, since 2×136721831² = 37385718143985122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136723831) 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, 68360915 + 68360916.

It is an arithmetic number, because the mean of its divisors is an integer number (68360916).

Almost surely, 2^136721831 is an apocalyptic number.

136721831 is a deficient number, since it is larger than the sum of its proper divisors (1).

136721831 is an equidigital number, since it uses as much as digits as its factorization.

136721831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 32.

The square root of 136721831 is about 11692.8110820281. The cubic root of 136721831 is about 515.1645322161.

The spelling of 136721831 in words is "one hundred thirty-six million, seven hundred twenty-one thousand, eight hundred thirty-one".