21686696 has 32 divisors (see below), whose sum is σ = 43341480. Its totient is φ = 10137600.

The previous prime is 21686671. The next prime is 21686741. The reversal of 21686696 is 69668612.

It can be written as a sum of positive squares in 4 ways, for example, as 11356900 + 10329796 = 3370^2 + 3214^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24176 + ... + 25056.

Almost surely, 2^21686696 is an apocalyptic number.

It is an amenable number.

21686696 is a deficient number, since it is larger than the sum of its proper divisors (21654784).

21686696 is a wasteful number, since it uses less digits than its factorization.

21686696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1085 (or 1081 counting only the distinct ones).

The product of its digits is 186624, while the sum is 44.

The square root of 21686696 is about 4656.8976797864. The cubic root of 21686696 is about 278.8674318702.

The spelling of 21686696 in words is "twenty-one million, six hundred eighty-six thousand, six hundred ninety-six".