21079799 has 8 divisors (see below), whose sum is σ = 23688672. Its totient is φ = 18612000.

The previous prime is 21079789. The next prime is 21079801. The reversal of 21079799 is 99797012.

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 21079799 - 2²⁰ = 20031223 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 (21079769) 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, 34952 + ... + 35549.

It is an arithmetic number, because the mean of its divisors is an integer number (2961084).

Almost surely, 2^21079799 is an apocalyptic number.

21079799 is a deficient number, since it is larger than the sum of its proper divisors (2608873).

21079799 is a wasteful number, since it uses less digits than its factorization.

21079799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70537.

The product of its (nonzero) digits is 71442, while the sum is 44.

The square root of 21079799 is about 4591.2742240036. The cubic root of 21079799 is about 276.2414352770.

The spelling of 21079799 in words is "twenty-one million, seventy-nine thousand, seven hundred ninety-nine".