21879495 has 24 divisors (see below), whose sum is σ = 41373072. Its totient is φ = 10608000.

The previous prime is 21879491. The next prime is 21879497. The reversal of 21879495 is 59497812.

It is not a de Polignac number, because 21879495 - 2² = 21879491 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21879495.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21879491) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21606 + ... + 22595.

It is an arithmetic number, because the mean of its divisors is an integer number (1723878).

Almost surely, 2^21879495 is an apocalyptic number.

21879495 is a deficient number, since it is larger than the sum of its proper divisors (19493577).

21879495 is a wasteful number, since it uses less digits than its factorization.

21879495 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44223 (or 44220 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 21879495 is about 4677.5522444971. The cubic root of 21879495 is about 279.6913904247.

The spelling of 21879495 in words is "twenty-one million, eight hundred seventy-nine thousand, four hundred ninety-five".