21696516 has 36 divisors (see below), whose sum is σ = 56015232. Its totient is φ = 7077744.

The previous prime is 21696511. The next prime is 21696529. The reversal of 21696516 is 61569612.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21696511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4720 + ... + 8103.

Almost surely, 2^21696516 is an apocalyptic number.

It is an amenable number.

21696516 is an abundant number, since it is smaller than the sum of its proper divisors (34318716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21696516 is a wasteful number, since it uses less digits than its factorization.

21696516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12880 (or 12875 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 21696516 is about 4657.9519104430. The cubic root of 21696516 is about 278.9095170415.

The spelling of 21696516 in words is "twenty-one million, six hundred ninety-six thousand, five hundred sixteen".