21082513 has 8 divisors (see below), whose sum is σ = 22511808. Its totient is φ = 19695984.

The previous prime is 21082483. The next prime is 21082517. The reversal of 21082513 is 31528012.

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 21082513 - 2¹³ = 21074321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21082517) 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, 9670 + ... + 11647.

It is an arithmetic number, because the mean of its divisors is an integer number (2813976).

Almost surely, 2^21082513 is an apocalyptic number.

21082513 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21082513 is a deficient number, since it is larger than the sum of its proper divisors (1429295).

21082513 is a wasteful number, since it uses less digits than its factorization.

21082513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21383.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 21082513 is about 4591.5697751423. The cubic root of 21082513 is about 276.2532900245.

The spelling of 21082513 in words is "twenty-one million, eighty-two thousand, five hundred thirteen".