21928351 has 8 divisors (see below), whose sum is σ = 23499504. Its totient is φ = 20388480.

The previous prime is 21928343. The next prime is 21928381. The reversal of 21928351 is 15382912.

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

It is a cyclic number.

It is not a de Polignac number, because 21928351 - 2³ = 21928343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21928301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6360 + ... + 9181.

It is an arithmetic number, because the mean of its divisors is an integer number (2937438).

Almost surely, 2^21928351 is an apocalyptic number.

21928351 is a deficient number, since it is larger than the sum of its proper divisors (1571153).

21928351 is a wasteful number, since it uses less digits than its factorization.

21928351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15641.

The product of its digits is 4320, while the sum is 31.

The square root of 21928351 is about 4682.7717219613. The cubic root of 21928351 is about 279.8994154019.

The spelling of 21928351 in words is "twenty-one million, nine hundred twenty-eight thousand, three hundred fifty-one".