135913681 has 4 divisors (see below), whose sum is σ = 135977472. Its totient is φ = 135849892.

The previous prime is 135913643. The next prime is 135913697. The reversal of 135913681 is 186319531.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 135913681 - 2⁷ = 135913553 is a prime.

It is a super-2 number, since 2×135913681² = 36945057365939522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 135913681.

It is not an unprimeable number, because it can be changed into a prime (135913621) 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 in 3 ways as a sum of consecutive naturals, for example, 28585 + ... + 32998.

It is an arithmetic number, because the mean of its divisors is an integer number (33994368).

Almost surely, 2^135913681 is an apocalyptic number.

It is an amenable number.

135913681 is a deficient number, since it is larger than the sum of its proper divisors (63791).

135913681 is an equidigital number, since it uses as much as digits as its factorization.

135913681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63790.

The product of its digits is 19440, while the sum is 37.

The square root of 135913681 is about 11658.2023056730. The cubic root of 135913681 is about 514.1474958623.

The spelling of 135913681 in words is "one hundred thirty-five million, nine hundred thirteen thousand, six hundred eighty-one".