21372552 has 32 divisors (see below), whose sum is σ = 59368800. Its totient is φ = 7124112.

The previous prime is 21372551. The next prime is 21372563. The reversal of 21372552 is 25527312.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21372551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49258 + ... + 49689.

It is an arithmetic number, because the mean of its divisors is an integer number (1855275).

Almost surely, 2^21372552 is an apocalyptic number.

It is an amenable number.

21372552 is an abundant number, since it is smaller than the sum of its proper divisors (37996248).

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

21372552 is a wasteful number, since it uses less digits than its factorization.

21372552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98962 (or 98952 counting only the distinct ones).

The product of its digits is 4200, while the sum is 27.

The square root of 21372552 is about 4623.0457492869. The cubic root of 21372552 is about 277.5143601042.

Adding to 21372552 its reverse (25527312), we get a palindrome (46899864).

The spelling of 21372552 in words is "twenty-one million, three hundred seventy-two thousand, five hundred fifty-two".