21879465 has 8 divisors (see below), whose sum is σ = 35007168. Its totient is φ = 11669040.

The previous prime is 21879457. The next prime is 21879479. The reversal of 21879465 is 56497812.

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

It is not a de Polignac number, because 21879465 - 2³ = 21879457 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 729301 + ... + 729330.

It is an arithmetic number, because the mean of its divisors is an integer number (4375896).

Almost surely, 2^21879465 is an apocalyptic number.

It is an amenable number.

21879465 is a deficient number, since it is larger than the sum of its proper divisors (13127703).

21879465 is a wasteful number, since it uses less digits than its factorization.

21879465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1458639.

The product of its digits is 120960, while the sum is 42.

The square root of 21879465 is about 4677.5490376906. The cubic root of 21879465 is about 279.6912625920.

The spelling of 21879465 in words is "twenty-one million, eight hundred seventy-nine thousand, four hundred sixty-five".