21696716 has 18 divisors (see below), whose sum is σ = 38719212. Its totient is φ = 10638160.

The previous prime is 21696713. The next prime is 21696721. The reversal of 21696716 is 61769612.

It is a self number, because there is not a number n which added to its sum of digits gives 21696716.

It is not an unprimeable number, because it can be changed into a prime (21696713) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10271 + ... + 12201.

Almost surely, 2^21696716 is an apocalyptic number.

It is an amenable number.

21696716 is a deficient number, since it is larger than the sum of its proper divisors (17022496).

21696716 is a wasteful number, since it uses less digits than its factorization.

21696716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2041 (or 1986 counting only the distinct ones).

The product of its digits is 27216, while the sum is 38.

The square root of 21696716 is about 4657.9733790566. The cubic root of 21696716 is about 278.9103740413.

The spelling of 21696716 in words is "twenty-one million, six hundred ninety-six thousand, seven hundred sixteen".