21715694 has 32 divisors (see below), whose sum is σ = 43739136. Its totient is φ = 7809120.

The previous prime is 21715679. The next prime is 21715697. The reversal of 21715694 is 49651712.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21715697) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3422 + ... + 7425.

It is an arithmetic number, because the mean of its divisors is an integer number (1366848).

Almost surely, 2^21715694 is an apocalyptic number.

21715694 is an abundant number, since it is smaller than the sum of its proper divisors (22023442).

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

21715694 is a wasteful number, since it uses less digits than its factorization.

21715694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10880.

The product of its digits is 15120, while the sum is 35.

The square root of 21715694 is about 4660.0100858260. The cubic root of 21715694 is about 278.9916708073.

The spelling of 21715694 in words is "twenty-one million, seven hundred fifteen thousand, six hundred ninety-four".