21372252 has 24 divisors (see below), whose sum is σ = 54402432. Its totient is φ = 6476400.

The previous prime is 21372233. The next prime is 21372269. The reversal of 21372252 is 25227312.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80824 + ... + 81087.

It is an arithmetic number, because the mean of its divisors is an integer number (2266768).

Almost surely, 2^21372252 is an apocalyptic number.

21372252 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21372252 is an abundant number, since it is smaller than the sum of its proper divisors (33030180).

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

21372252 is a wasteful number, since it uses less digits than its factorization.

21372252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161929 (or 161927 counting only the distinct ones).

The product of its digits is 1680, while the sum is 24.

The square root of 21372252 is about 4623.0133030308. The cubic root of 21372252 is about 277.5130616366.

Adding to 21372252 its reverse (25227312), we get a palindrome (46599564).

It can be divided in two parts, 21 and 372252, that added together give a palindrome (372273).

The spelling of 21372252 in words is "twenty-one million, three hundred seventy-two thousand, two hundred fifty-two".