136621591 has 2 divisors, whose sum is σ = 136621592. Its totient is φ = 136621590.

The previous prime is 136621579. The next prime is 136621607. The reversal of 136621591 is 195126631.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 136621591 - 2¹¹ = 136619543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136621561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68310795 + 68310796.

It is an arithmetic number, because the mean of its divisors is an integer number (68310796).

Almost surely, 2^136621591 is an apocalyptic number.

136621591 is a deficient number, since it is larger than the sum of its proper divisors (1).

136621591 is an equidigital number, since it uses as much as digits as its factorization.

136621591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 34.

The square root of 136621591 is about 11688.5239016738. The cubic root of 136621591 is about 515.0386008079.

The spelling of 136621591 in words is "one hundred thirty-six million, six hundred twenty-one thousand, five hundred ninety-one".