21531190 has 16 divisors (see below), whose sum is σ = 38828160. Its totient is φ = 8596480.

The previous prime is 21531179. The next prime is 21531193. The reversal of 21531190 is 9113512.

It is a super-2 number, since 2×21531190² = 927184285632200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531193) 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, 4731 + ... + 8089.

It is an arithmetic number, because the mean of its divisors is an integer number (2426760).

Almost surely, 2^21531190 is an apocalyptic number.

21531190 is a deficient number, since it is larger than the sum of its proper divisors (17296970).

21531190 is a wasteful number, since it uses less digits than its factorization.

21531190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4007.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 21531190 is about 4640.1713330436. The cubic root of 21531190 is about 278.1992860525.

The spelling of 21531190 in words is "twenty-one million, five hundred thirty-one thousand, one hundred ninety".