21139339 has 8 divisors (see below), whose sum is σ = 22941072. Its totient is φ = 19362720.

The previous prime is 21139337. The next prime is 21139379. The reversal of 21139339 is 93393112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21139339 - 2¹ = 21139337 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21139339.

It is not an unprimeable number, because it can be changed into a prime (21139337) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4504 + ... + 7909.

It is an arithmetic number, because the mean of its divisors is an integer number (2867634).

Almost surely, 2^21139339 is an apocalyptic number.

21139339 is a deficient number, since it is larger than the sum of its proper divisors (1801733).

21139339 is a wasteful number, since it uses less digits than its factorization.

21139339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12557.

The product of its digits is 4374, while the sum is 31.

The square root of 21139339 is about 4597.7536906624. The cubic root of 21139339 is about 276.5012725750.

The spelling of 21139339 in words is "twenty-one million, one hundred thirty-nine thousand, three hundred thirty-nine".