21879159 has 8 divisors (see below), whose sum is σ = 29257200. Its totient is φ = 14543616.

The previous prime is 21879139. The next prime is 21879163. The reversal of 21879159 is 95197812.

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

It is not a de Polignac number, because 21879159 - 2¹³ = 21870967 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21879159.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21879139) 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, 9402 + ... + 11495.

It is an arithmetic number, because the mean of its divisors is an integer number (3657150).

Almost surely, 2^21879159 is an apocalyptic number.

21879159 is a deficient number, since it is larger than the sum of its proper divisors (7378041).

21879159 is a wasteful number, since it uses less digits than its factorization.

21879159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21249.

The product of its digits is 45360, while the sum is 42.

The square root of 21879159 is about 4677.5163281383. The cubic root of 21879159 is about 279.6899586917.

The spelling of 21879159 in words is "twenty-one million, eight hundred seventy-nine thousand, one hundred fifty-nine".