21921954 has 8 divisors (see below), whose sum is σ = 43843920. Its totient is φ = 7307316.

The previous prime is 21921919. The next prime is 21922007. The reversal of 21921954 is 45912912.

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

21921954 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1826824 + ... + 1826835.

It is an arithmetic number, because the mean of its divisors is an integer number (5480490).

Almost surely, 2^21921954 is an apocalyptic number.

21921954 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.

21921954 is a wasteful number, since it uses less digits than its factorization.

21921954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3653664.

The product of its digits is 6480, while the sum is 33.

The square root of 21921954 is about 4682.0886364955. The cubic root of 21921954 is about 279.8721950742.

The spelling of 21921954 in words is "twenty-one million, nine hundred twenty-one thousand, nine hundred fifty-four".