21058313 has 4 divisors (see below), whose sum is σ = 21133008. Its totient is φ = 20983620.

The previous prime is 21058283. The next prime is 21058337. The reversal of 21058313 is 31385012.

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 cyclic number.

It is not a de Polignac number, because 21058313 - 2⁶ = 21058249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21058343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36923 + ... + 37488.

It is an arithmetic number, because the mean of its divisors is an integer number (5283252).

Almost surely, 2^21058313 is an apocalyptic number.

It is an amenable number.

21058313 is a deficient number, since it is larger than the sum of its proper divisors (74695).

21058313 is an equidigital number, since it uses as much as digits as its factorization.

21058313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74694.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21058313 is about 4588.9337541525. The cubic root of 21058313 is about 276.1475485313.

The spelling of 21058313 in words is "twenty-one million, fifty-eight thousand, three hundred thirteen".