21857696 has 24 divisors (see below), whose sum is σ = 49180320. Its totient is φ = 9367488.

The previous prime is 21857687. The next prime is 21857711. The reversal of 21857696 is 69675812.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48566 + ... + 49013.

It is an arithmetic number, because the mean of its divisors is an integer number (2049180).

Almost surely, 2^21857696 is an apocalyptic number.

It is an amenable number.

21857696 is an abundant number, since it is smaller than the sum of its proper divisors (27322624).

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

21857696 is an equidigital number, since it uses as much as digits as its factorization.

21857696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97596 (or 97588 counting only the distinct ones).

The product of its digits is 181440, while the sum is 44.

The square root of 21857696 is about 4675.2214920793. The cubic root of 21857696 is about 279.5984720919.

The spelling of 21857696 in words is "twenty-one million, eight hundred fifty-seven thousand, six hundred ninety-six".