21358992 has 20 divisors (see below), whose sum is σ = 55177520. Its totient is φ = 7119648.

The previous prime is 21358979. The next prime is 21358999. The reversal of 21358992 is 29985312.

It is a self number, because there is not a number n which added to its sum of digits gives 21358992.

It is not an unprimeable number, because it can be changed into a prime (21358999) 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, 222442 + ... + 222537.

It is an arithmetic number, because the mean of its divisors is an integer number (2758876).

Almost surely, 2^21358992 is an apocalyptic number.

It is an amenable number.

21358992 is an abundant number, since it is smaller than the sum of its proper divisors (33818528).

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

21358992 is a wasteful number, since it uses less digits than its factorization.

21358992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444990 (or 444984 counting only the distinct ones).

The product of its digits is 38880, while the sum is 39.

The square root of 21358992 is about 4621.5789509647. The cubic root of 21358992 is about 277.4556572276.

The spelling of 21358992 in words is "twenty-one million, three hundred fifty-eight thousand, nine hundred ninety-two".