21367313 has 4 divisors (see below), whose sum is σ = 23309808. Its totient is φ = 19424820.

The previous prime is 21367309. The next prime is 21367331. The reversal of 21367313 is 31376312.

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 21367313 - 2² = 21367309 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21367393) 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, 971231 + ... + 971252.

It is an arithmetic number, because the mean of its divisors is an integer number (5827452).

Almost surely, 2^21367313 is an apocalyptic number.

It is an amenable number.

21367313 is a deficient number, since it is larger than the sum of its proper divisors (1942495).

21367313 is a wasteful number, since it uses less digits than its factorization.

21367313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1942494.

The product of its digits is 2268, while the sum is 26.

The square root of 21367313 is about 4622.4790967618. The cubic root of 21367313 is about 277.4916827851.

It can be divided in two parts, 2136 and 7313, that added together give a palindrome (9449).

The spelling of 21367313 in words is "twenty-one million, three hundred sixty-seven thousand, three hundred thirteen".