21079513 has 8 divisors (see below), whose sum is σ = 25944128. Its totient is φ = 16678224.

The previous prime is 21079501. The next prime is 21079519. The reversal of 21079513 is 31597012.

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 21079513 - 2⁵ = 21079481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21079519) 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, 115731 + ... + 115912.

It is an arithmetic number, because the mean of its divisors is an integer number (3243016).

Almost surely, 2^21079513 is an apocalyptic number.

It is an amenable number.

21079513 is a deficient number, since it is larger than the sum of its proper divisors (4864615).

21079513 is a wasteful number, since it uses less digits than its factorization.

21079513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231663.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 21079513 is about 4591.2430778603. The cubic root of 21079513 is about 276.2401859702.

The spelling of 21079513 in words is "twenty-one million, seventy-nine thousand, five hundred thirteen".