21175490 has 16 divisors (see below), whose sum is σ = 43561152. Its totient is φ = 7260144.

The previous prime is 21175487. The next prime is 21175499. The reversal of 21175490 is 9457112.

It is not an unprimeable number, because it can be changed into a prime (21175499) 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, 151184 + ... + 151323.

It is an arithmetic number, because the mean of its divisors is an integer number (2722572).

Almost surely, 2^21175490 is an apocalyptic number.

21175490 is an abundant number, since it is smaller than the sum of its proper divisors (22385662).

21175490 is a wasteful number, since it uses less digits than its factorization.

21175490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302521.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 21175490 is about 4601.6833876311. The cubic root of 21175490 is about 276.6588004409.

The spelling of 21175490 in words is "twenty-one million, one hundred seventy-five thousand, four hundred ninety".