21898079 has 8 divisors (see below), whose sum is σ = 25400448. Its totient is φ = 18489240.

The previous prime is 21898067. The next prime is 21898087. The reversal of 21898079 is 97089812.

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

It is not a de Polignac number, because 21898079 - 2²⁰ = 20849503 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 7 ways as a sum of consecutive naturals, for example, 22877 + ... + 23814.

It is an arithmetic number, because the mean of its divisors is an integer number (3175056).

Almost surely, 2^21898079 is an apocalyptic number.

21898079 is a deficient number, since it is larger than the sum of its proper divisors (3502369).

21898079 is an equidigital number, since it uses as much as digits as its factorization.

21898079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46765.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 21898079 is about 4679.5383319298. The cubic root of 21898079 is about 279.7705560829.

The spelling of 21898079 in words is "twenty-one million, eight hundred ninety-eight thousand, seventy-nine".