21339788 has 12 divisors (see below), whose sum is σ = 37389072. Its totient is φ = 10657200.

The previous prime is 21339781. The next prime is 21339809. The reversal of 21339788 is 88793312.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21339781) 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, 1313 + ... + 6663.

It is an arithmetic number, because the mean of its divisors is an integer number (3115756).

Almost surely, 2^21339788 is an apocalyptic number.

It is an amenable number.

21339788 is a deficient number, since it is larger than the sum of its proper divisors (16049284).

21339788 is a wasteful number, since it uses less digits than its factorization.

21339788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6352 (or 6350 counting only the distinct ones).

The product of its digits is 72576, while the sum is 41.

The square root of 21339788 is about 4619.5008388353. The cubic root of 21339788 is about 277.3724782691.

The spelling of 21339788 in words is "twenty-one million, three hundred thirty-nine thousand, seven hundred eighty-eight".