136356991 has 4 divisors (see below), whose sum is σ = 138277584. Its totient is φ = 134436400.

The previous prime is 136356937. The next prime is 136357027. The reversal of 136356991 is 199653631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199653631 = 2477 ⋅80603.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-136356991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136356931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 960190 + ... + 960331.

It is an arithmetic number, because the mean of its divisors is an integer number (34569396).

Almost surely, 2^136356991 is an apocalyptic number.

136356991 is a deficient number, since it is larger than the sum of its proper divisors (1920593).

136356991 is an equidigital number, since it uses as much as digits as its factorization.

136356991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1920592.

The product of its digits is 131220, while the sum is 43.

The square root of 136356991 is about 11677.1996214846. The cubic root of 136356991 is about 514.7058879316.

The spelling of 136356991 in words is "one hundred thirty-six million, three hundred fifty-six thousand, nine hundred ninety-one".