21102136 has 32 divisors (see below), whose sum is σ = 44336880. Its totient is φ = 9331200.

The previous prime is 21102113. The next prime is 21102161. The reversal of 21102136 is 63120112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16 + ... + 6496.

Almost surely, 2^21102136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21102136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22168440).

21102136 is an abundant number, since it is smaller than the sum of its proper divisors (23234744).

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

21102136 is a wasteful number, since it uses less digits than its factorization.

21102136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6535 (or 6531 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21102136 is about 4593.7061290422. The cubic root of 21102136 is about 276.3389729995.

Adding to 21102136 its reverse (63120112), we get a palindrome (84222248).

The spelling of 21102136 in words is "twenty-one million, one hundred two thousand, one hundred thirty-six".