21804297 has 8 divisors (see below), whose sum is σ = 29470944. Its totient is φ = 14336928.

The previous prime is 21804283. The next prime is 21804329. The reversal of 21804297 is 79240812.

It is a happy number.

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

It is not a de Polignac number, because 21804297 - 2⁴ = 21804281 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21804227) 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 7 ways as a sum of consecutive naturals, for example, 49563 + ... + 50000.

It is an arithmetic number, because the mean of its divisors is an integer number (3683868).

Almost surely, 2^21804297 is an apocalyptic number.

It is an amenable number.

21804297 is a deficient number, since it is larger than the sum of its proper divisors (7666647).

21804297 is an equidigital number, since it uses as much as digits as its factorization.

21804297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99639.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 21804297 is about 4669.5071474407. The cubic root of 21804297 is about 279.3705973011.

The spelling of 21804297 in words is "twenty-one million, eight hundred four thousand, two hundred ninety-seven".