21339394 has 16 divisors (see below), whose sum is σ = 33948000. Its totient is φ = 10031904.

The previous prime is 21339391. The next prime is 21339397. The reversal of 21339394 is 49393312.

It is an interprime number because it is at equal distance from previous prime (21339391) and next prime (21339397).

It is not an unprimeable number, because it can be changed into a prime (21339391) 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, 3157 + ... + 7255.

It is an arithmetic number, because the mean of its divisors is an integer number (2121750).

Almost surely, 2^21339394 is an apocalyptic number.

21339394 is a deficient number, since it is larger than the sum of its proper divisors (12608606).

21339394 is a wasteful number, since it uses less digits than its factorization.

21339394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4257.

The product of its digits is 17496, while the sum is 34.

The square root of 21339394 is about 4619.4581933383. The cubic root of 21339394 is about 277.3707712008.

The spelling of 21339394 in words is "twenty-one million, three hundred thirty-nine thousand, three hundred ninety-four".