136821638 has 16 divisors (see below), whose sum is σ = 209017584. Its totient is φ = 67156320.

The previous prime is 136821583. The next prime is 136821689. The reversal of 136821638 is 836128631.

136821638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40868 + ... + 44088.

It is an arithmetic number, because the mean of its divisors is an integer number (13063599).

Almost surely, 2^136821638 is an apocalyptic number.

136821638 is a deficient number, since it is larger than the sum of its proper divisors (72195946).

136821638 is a wasteful number, since it uses less digits than its factorization.

136821638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3607.

The product of its digits is 41472, while the sum is 38.

The square root of 136821638 is about 11697.0781821787. The cubic root of 136821638 is about 515.2898585074.

The spelling of 136821638 in words is "one hundred thirty-six million, eight hundred twenty-one thousand, six hundred thirty-eight".