21838879 has 8 divisors (see below), whose sum is σ = 22480128. Its totient is φ = 21205080.

The previous prime is 21838867. The next prime is 21838889. The reversal of 21838879 is 97883812.

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

It is a cyclic number.

It is not a de Polignac number, because 21838879 - 2¹³ = 21830687 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 (21838889) 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, 4384 + ... + 7930.

It is an arithmetic number, because the mean of its divisors is an integer number (2810016).

Almost surely, 2^21838879 is an apocalyptic number.

21838879 is a deficient number, since it is larger than the sum of its proper divisors (641249).

21838879 is a wasteful number, since it uses less digits than its factorization.

21838879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3725.

The product of its digits is 193536, while the sum is 46.

The square root of 21838879 is about 4673.2086407521. The cubic root of 21838879 is about 279.5182148538.

The spelling of 21838879 in words is "twenty-one million, eight hundred thirty-eight thousand, eight hundred seventy-nine".