21707396 has 6 divisors (see below), whose sum is σ = 37987950. Its totient is φ = 10853696.

The previous prime is 21707393. The next prime is 21707401. The reversal of 21707396 is 69370712.

It can be written as a sum of positive squares in only one way, i.e., 18232900 + 3474496 = 4270^2 + 1864^2 .

It is a super-2 number, since 2×21707396² = 942422082201632, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21707393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2713421 + ... + 2713428.

It is an arithmetic number, because the mean of its divisors is an integer number (6331325).

Almost surely, 2^21707396 is an apocalyptic number.

It is an amenable number.

21707396 is a deficient number, since it is larger than the sum of its proper divisors (16280554).

21707396 is a wasteful number, since it uses less digits than its factorization.

21707396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5426853 (or 5426851 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 35.

The square root of 21707396 is about 4659.1196593348. The cubic root of 21707396 is about 278.9561301852.

The spelling of 21707396 in words is "twenty-one million, seven hundred seven thousand, three hundred ninety-six".