21879119 has 4 divisors (see below), whose sum is σ = 23166144. Its totient is φ = 20592096.

The previous prime is 21879103. The next prime is 21879139. The reversal of 21879119 is 91197812.

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

It is a cyclic number.

It is not a de Polignac number, because 21879119 - 2⁴ = 21879103 is a prime.

It is a super-2 number, since 2×21879119² = 957391696432322, which contains 22 as substring.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 643487 + ... + 643520.

It is an arithmetic number, because the mean of its divisors is an integer number (5791536).

Almost surely, 2^21879119 is an apocalyptic number.

21879119 is a deficient number, since it is larger than the sum of its proper divisors (1287025).

21879119 is a wasteful number, since it uses less digits than its factorization.

21879119 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287024.

The product of its digits is 9072, while the sum is 38.

The square root of 21879119 is about 4677.5120523629. The cubic root of 21879119 is about 279.6897882463.

The spelling of 21879119 in words is "twenty-one million, eight hundred seventy-nine thousand, one hundred nineteen".