21074839 has 8 divisors (see below), whose sum is σ = 21359952. Its totient is φ = 20791680.

The previous prime is 21074813. The next prime is 21074843. The reversal of 21074839 is 93847012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21074839 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 (21074239) 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, 47352 + ... + 47794.

It is an arithmetic number, because the mean of its divisors is an integer number (2669994).

Almost surely, 2^21074839 is an apocalyptic number.

21074839 is a deficient number, since it is larger than the sum of its proper divisors (285113).

21074839 is a wasteful number, since it uses less digits than its factorization.

21074839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 977.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 21074839 is about 4590.7340371666. The cubic root of 21074839 is about 276.2197673759.

The spelling of 21074839 in words is "twenty-one million, seventy-four thousand, eight hundred thirty-nine".