21696678 has 24 divisors (see below), whose sum is σ = 47429928. Its totient is φ = 7167552.

The previous prime is 21696629. The next prime is 21696707. The reversal of 21696678 is 87669612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3300 + ... + 7367.

It is an arithmetic number, because the mean of its divisors is an integer number (1976247).

Almost surely, 2^21696678 is an apocalyptic number.

21696678 is an abundant number, since it is smaller than the sum of its proper divisors (25733250).

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

21696678 is a wasteful number, since it uses less digits than its factorization.

21696678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10788 (or 10785 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 21696678 is about 4657.9693000276. The cubic root of 21696678 is about 278.9102112118.

The spelling of 21696678 in words is "twenty-one million, six hundred ninety-six thousand, six hundred seventy-eight".