21693686 has 8 divisors (see below), whose sum is σ = 37189200. Its totient is φ = 9297288.

The previous prime is 21693673. The next prime is 21693697. The reversal of 21693686 is 68639612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

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, 774761 + ... + 774788.

It is an arithmetic number, because the mean of its divisors is an integer number (4648650).

Almost surely, 2^21693686 is an apocalyptic number.

21693686 is a deficient number, since it is larger than the sum of its proper divisors (15495514).

21693686 is a wasteful number, since it uses less digits than its factorization.

21693686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1549558.

The product of its digits is 93312, while the sum is 41.

The square root of 21693686 is about 4657.6481189545. The cubic root of 21693686 is about 278.8973899293.

The spelling of 21693686 in words is "twenty-one million, six hundred ninety-three thousand, six hundred eighty-six".