21164190 has 32 divisors (see below), whose sum is σ = 50941440. Its totient is φ = 5627424.

The previous prime is 21164189. The next prime is 21164237. The reversal of 21164190 is 9146112.

It is a super-2 number, since 2×21164190² = 895845876712200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21164190.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12367 + ... + 13973.

It is an arithmetic number, because the mean of its divisors is an integer number (1591920).

Almost surely, 2^21164190 is an apocalyptic number.

21164190 is an abundant number, since it is smaller than the sum of its proper divisors (29777250).

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

21164190 is a wasteful number, since it uses less digits than its factorization.

21164190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2056.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 21164190 is about 4600.4554122391. The cubic root of 21164190 is about 276.6095800025.

The spelling of 21164190 in words is "twenty-one million, one hundred sixty-four thousand, one hundred ninety".