21319139 has 16 divisors (see below), whose sum is σ = 23496480. Its totient is φ = 19261440.

The previous prime is 21319127. The next prime is 21319169. The reversal of 21319139 is 93191312.

It is a cyclic number.

It is not a de Polignac number, because 21319139 - 2²⁰ = 20270563 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (21319169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50672 + ... + 51090.

It is an arithmetic number, because the mean of its divisors is an integer number (1468530).

Almost surely, 2^21319139 is an apocalyptic number.

21319139 is a deficient number, since it is larger than the sum of its proper divisors (2177341).

21319139 is a wasteful number, since it uses less digits than its factorization.

21319139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550.

The product of its digits is 1458, while the sum is 29.

The square root of 21319139 is about 4617.2653161801. The cubic root of 21319139 is about 277.2829848363.

The spelling of 21319139 in words is "twenty-one million, three hundred nineteen thousand, one hundred thirty-nine".