21312694 has 8 divisors (see below), whose sum is σ = 34428240. Its totient is φ = 9836616.

The previous prime is 21312677. The next prime is 21312721. The reversal of 21312694 is 49621312.

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, 409834 + ... + 409885.

It is an arithmetic number, because the mean of its divisors is an integer number (4303530).

Almost surely, 2^21312694 is an apocalyptic number.

21312694 is a deficient number, since it is larger than the sum of its proper divisors (13115546).

21312694 is a wasteful number, since it uses less digits than its factorization.

21312694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819734.

The product of its digits is 2592, while the sum is 28.

The square root of 21312694 is about 4616.5673394850. The cubic root of 21312694 is about 277.2550401657.

The spelling of 21312694 in words is "twenty-one million, three hundred twelve thousand, six hundred ninety-four".