21924797 has 4 divisors (see below), whose sum is σ = 22434720. Its totient is φ = 21414876.

The previous prime is 21924787. The next prime is 21924817. The reversal of 21924797 is 79742912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21924797 - 2⁶ = 21924733 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 (21924737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254897 + ... + 254982.

It is an arithmetic number, because the mean of its divisors is an integer number (5608680).

Almost surely, 2^21924797 is an apocalyptic number.

It is an amenable number.

21924797 is a deficient number, since it is larger than the sum of its proper divisors (509923).

21924797 is an equidigital number, since it uses as much as digits as its factorization.

21924797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509922.

The product of its digits is 63504, while the sum is 41.

The square root of 21924797 is about 4682.3922304736. The cubic root of 21924797 is about 279.8842931785.

The spelling of 21924797 in words is "twenty-one million, nine hundred twenty-four thousand, seven hundred ninety-seven".