21182990 has 8 divisors (see below), whose sum is σ = 38129400. Its totient is φ = 8473192.

The previous prime is 21182989. The next prime is 21182999. The reversal of 21182990 is 9928112.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21182999) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1059140 + ... + 1059159.

It is an arithmetic number, because the mean of its divisors is an integer number (4766175).

Almost surely, 2^21182990 is an apocalyptic number.

21182990 is a deficient number, since it is larger than the sum of its proper divisors (16946410).

21182990 is a wasteful number, since it uses less digits than its factorization.

21182990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2118306.

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 21182990 is about 4602.4982346547. The cubic root of 21182990 is about 276.6914592063.

The spelling of 21182990 in words is "twenty-one million, one hundred eighty-two thousand, nine hundred ninety".