21898479 has 4 divisors (see below), whose sum is σ = 29197976. Its totient is φ = 14598984.

The previous prime is 21898453. The next prime is 21898501. The reversal of 21898479 is 97489812.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21898479 - 2⁵ = 21898447 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 (21898379) 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, 3649744 + ... + 3649749.

It is an arithmetic number, because the mean of its divisors is an integer number (7299494).

Almost surely, 2^21898479 is an apocalyptic number.

21898479 is a deficient number, since it is larger than the sum of its proper divisors (7299497).

21898479 is an equidigital number, since it uses as much as digits as its factorization.

21898479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7299496.

The product of its digits is 290304, while the sum is 48.

The square root of 21898479 is about 4679.5810709934. The cubic root of 21898479 is about 279.7722595434.

The spelling of 21898479 in words is "twenty-one million, eight hundred ninety-eight thousand, four hundred seventy-nine".