136231821 has 32 divisors (see below), whose sum is σ = 227779200. Its totient is φ = 79712640.

The previous prime is 136231819. The next prime is 136231847. The reversal of 136231821 is 128132631.

It is a happy number.

136231821 is a `hidden beast` number, since 1 + 3 + 623 + 18 + 21 = 666.

It is not a de Polignac number, because 136231821 - 2¹ = 136231819 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136231861) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 705 + ... + 16521.

It is an arithmetic number, because the mean of its divisors is an integer number (7118100).

Almost surely, 2^136231821 is an apocalyptic number.

136231821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

136231821 is a deficient number, since it is larger than the sum of its proper divisors (91547379).

136231821 is a wasteful number, since it uses less digits than its factorization.

136231821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15866 (or 15860 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 136231821 is about 11671.8388011487. The cubic root of 136231821 is about 514.5483469090.

The spelling of 136231821 in words is "one hundred thirty-six million, two hundred thirty-one thousand, eight hundred twenty-one".