136615021 has 4 divisors (see below), whose sum is σ = 136784700. Its totient is φ = 136445344.

The previous prime is 136615001. The next prime is 136615049. The reversal of 136615021 is 120516631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120516631 = 6037 ⋅19963.

It can be written as a sum of positive squares in 2 ways, for example, as 67076100 + 69538921 = 8190^2 + 8339^2 .

It is a cyclic number.

It is not a de Polignac number, because 136615021 - 2²⁵ = 103060589 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 (136615001) 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, 83626 + ... + 85243.

It is an arithmetic number, because the mean of its divisors is an integer number (34196175).

Almost surely, 2^136615021 is an apocalyptic number.

It is an amenable number.

136615021 is a deficient number, since it is larger than the sum of its proper divisors (169679).

136615021 is an equidigital number, since it uses as much as digits as its factorization.

136615021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169678.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 136615021 is about 11688.2428533976. The cubic root of 136615021 is about 515.0303447731.

The spelling of 136615021 in words is "one hundred thirty-six million, six hundred fifteen thousand, twenty-one".