21331319 has 4 divisors (see below), whose sum is σ = 22454040. Its totient is φ = 20208600.

The previous prime is 21331313. The next prime is 21331333. The reversal of 21331319 is 91313312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21331319 - 2¹² = 21327223 is a prime.

It is a super-2 number, since 2×21331319² = 910050340559522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21331294 and 21331303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331313) 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, 561332 + ... + 561369.

It is an arithmetic number, because the mean of its divisors is an integer number (5613510).

Almost surely, 2^21331319 is an apocalyptic number.

21331319 is a deficient number, since it is larger than the sum of its proper divisors (1122721).

21331319 is a wasteful number, since it uses less digits than its factorization.

21331319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122720.

The product of its digits is 486, while the sum is 23.

The square root of 21331319 is about 4618.5840903896. The cubic root of 21331319 is about 277.3357803360.

The spelling of 21331319 in words is "twenty-one million, three hundred thirty-one thousand, three hundred nineteen".