21332990 has 16 divisors (see below), whose sum is σ = 43885152. Its totient is φ = 7314144.

The previous prime is 21332963. The next prime is 21333007. The reversal of 21332990 is 9923312.

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, 152309 + ... + 152448.

It is an arithmetic number, because the mean of its divisors is an integer number (2742822).

Almost surely, 2^21332990 is an apocalyptic number.

21332990 is an abundant number, since it is smaller than the sum of its proper divisors (22552162).

21332990 is a wasteful number, since it uses less digits than its factorization.

21332990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304771.

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 21332990 is about 4618.7649864439. The cubic root of 21332990 is about 277.3430218945.

It can be divided in two parts, 21332 and 990, that added together give a palindrome (22322).

The spelling of 21332990 in words is "twenty-one million, three hundred thirty-two thousand, nine hundred ninety".