21402132 has 96 divisors (see below), whose sum is σ = 56179200. Its totient is φ = 6314112.

The previous prime is 21402119. The next prime is 21402137. The reversal of 21402132 is 23120412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402137) 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, 362719 + ... + 362777.

It is an arithmetic number, because the mean of its divisors is an integer number (585200).

Almost surely, 2^21402132 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 21402132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28089600).

21402132 is an abundant number, since it is smaller than the sum of its proper divisors (34777068).

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

21402132 is a wasteful number, since it uses less digits than its factorization.

21402132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21402132 is about 4626.2438327438. The cubic root of 21402132 is about 277.6423293894.

Adding to 21402132 its reverse (23120412), we get a palindrome (44522544).

The spelling of 21402132 in words is "twenty-one million, four hundred two thousand, one hundred thirty-two".