21851922 has 8 divisors (see below), whose sum is σ = 43703856. Its totient is φ = 7283972.

The previous prime is 21851917. The next prime is 21851923. The reversal of 21851922 is 22915812.

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

21851922 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 21851922.

It is not an unprimeable number, because it can be changed into a prime (21851923) by changing a digit.

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, 1820988 + ... + 1820999.

It is an arithmetic number, because the mean of its divisors is an integer number (5462982).

Almost surely, 2^21851922 is an apocalyptic number.

21851922 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21851922 is a wasteful number, since it uses less digits than its factorization.

21851922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3641992.

The product of its digits is 2880, while the sum is 30.

The square root of 21851922 is about 4674.6039404424. The cubic root of 21851922 is about 279.5738500434.

The spelling of 21851922 in words is "twenty-one million, eight hundred fifty-one thousand, nine hundred twenty-two".