21551190 has 32 divisors (see below), whose sum is σ = 51965280. Its totient is φ = 5720064.

The previous prime is 21551177. The next prime is 21551221. The reversal of 21551190 is 9115512.

It is a super-2 number, since 2×21551190² = 928907580832200, 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 21551190.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5302 + ... + 8438.

It is an arithmetic number, because the mean of its divisors is an integer number (1623915).

Almost surely, 2^21551190 is an apocalyptic number.

21551190 is an abundant number, since it is smaller than the sum of its proper divisors (30414090).

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

21551190 is a wasteful number, since it uses less digits than its factorization.

21551190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3376.

The product of its (nonzero) digits is 450, while the sum is 24.

The square root of 21551190 is about 4642.3259256541. The cubic root of 21551190 is about 278.2853977791.

The spelling of 21551190 in words is "twenty-one million, five hundred fifty-one thousand, one hundred ninety".