21095013 has 4 divisors (see below), whose sum is σ = 28126688. Its totient is φ = 14063340.

The previous prime is 21095003. The next prime is 21095021. The reversal of 21095013 is 31059012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-21095013 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 (21095003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3515833 + ... + 3515838.

It is an arithmetic number, because the mean of its divisors is an integer number (7031672).

Almost surely, 2^21095013 is an apocalyptic number.

It is an amenable number.

21095013 is a deficient number, since it is larger than the sum of its proper divisors (7031675).

21095013 is an equidigital number, since it uses as much as digits as its factorization.

21095013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7031674.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 21095013 is about 4592.9307636846. The cubic root of 21095013 is about 276.3078768738.

The spelling of 21095013 in words is "twenty-one million, ninety-five thousand, thirteen".