21102132 has 48 divisors (see below), whose sum is σ = 51956352. Its totient is φ = 6652800.

The previous prime is 21102113. The next prime is 21102161. The reversal of 21102132 is 23120112.

It is a Harshad number since it is a multiple of its sum of digits (12).

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 15 ways as a sum of consecutive naturals, for example, 27498 + ... + 28254.

It is an arithmetic number, because the mean of its divisors is an integer number (1082424).

Almost surely, 2^21102132 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 21102132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25978176).

21102132 is an abundant number, since it is smaller than the sum of its proper divisors (30854220).

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

21102132 is a wasteful number, since it uses less digits than its factorization.

21102132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888 (or 886 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21102132 is about 4593.7056936639. The cubic root of 21102132 is about 276.3389555390.

Adding to 21102132 its reverse (23120112), we get a palindrome (44222244).

The spelling of 21102132 in words is "twenty-one million, one hundred two thousand, one hundred thirty-two".