21339693 has 20 divisors (see below), whose sum is σ = 32183580. Its totient is φ = 14090112.

The previous prime is 21339677. The next prime is 21339733. The reversal of 21339693 is 39693312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18507204 + 2832489 = 4302^2 + 1683^2 .

It is not a de Polignac number, because 21339693 - 2⁴ = 21339677 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21339673) 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 19 ways as a sum of consecutive naturals, for example, 7621 + ... + 10037.

It is an arithmetic number, because the mean of its divisors is an integer number (1609179).

Almost surely, 2^21339693 is an apocalyptic number.

It is an amenable number.

21339693 is a deficient number, since it is larger than the sum of its proper divisors (10843887).

21339693 is a wasteful number, since it uses less digits than its factorization.

21339693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2538 (or 2529 counting only the distinct ones).

The product of its digits is 26244, while the sum is 36.

The square root of 21339693 is about 4619.4905563276. The cubic root of 21339693 is about 277.3720666683.

The spelling of 21339693 in words is "twenty-one million, three hundred thirty-nine thousand, six hundred ninety-three".