21536136 has 24 divisors (see below), whose sum is σ = 58327230. Its totient is φ = 7178688.

The previous prime is 21536117. The next prime is 21536143. The reversal of 21536136 is 63163512.

It can be written as a sum of positive squares in only one way, i.e., 20304036 + 1232100 = 4506^2 + 1110^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 149485 + ... + 149628.

Almost surely, 2^21536136 is an apocalyptic number.

It is an amenable number.

21536136 is an abundant number, since it is smaller than the sum of its proper divisors (36791094).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21536136 is a wasteful number, since it uses less digits than its factorization.

21536136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299125 (or 299118 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 21536136 is about 4640.7042568989. The cubic root of 21536136 is about 278.2205864438.

Adding to 21536136 its reverse (63163512), we get a palindrome (84699648).

The spelling of 21536136 in words is "twenty-one million, five hundred thirty-six thousand, one hundred thirty-six".