21621190 has 8 divisors (see below), whose sum is σ = 38918160. Its totient is φ = 8648472.

The previous prime is 21621181. The next prime is 21621233. The reversal of 21621190 is 9112612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21621190² = 934951714032200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1081050 + ... + 1081069.

It is an arithmetic number, because the mean of its divisors is an integer number (4864770).

Almost surely, 2^21621190 is an apocalyptic number.

21621190 is a deficient number, since it is larger than the sum of its proper divisors (17296970).

21621190 is a wasteful number, since it uses less digits than its factorization.

21621190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2162126.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 21621190 is about 4649.8591376514. The cubic root of 21621190 is about 278.5863699447.

The spelling of 21621190 in words is "twenty-one million, six hundred twenty-one thousand, one hundred ninety".