21717294709 has 32 divisors (see below), whose sum is σ = 25352271360. Its totient is φ = 18394516800.

The previous prime is 21717294701. The next prime is 21717294713. The reversal of 21717294709 is 90749271712.

It is not a de Polignac number, because 21717294709 - 2³ = 21717294701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21717294701) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14184274 + ... + 14185804.

It is an arithmetic number, because the mean of its divisors is an integer number (792258480).

Almost surely, 2^21717294709 is an apocalyptic number.

It is an amenable number.

21717294709 is a deficient number, since it is larger than the sum of its proper divisors (3634976651).

21717294709 is a wasteful number, since it uses less digits than its factorization.

21717294709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2641.

The product of its (nonzero) digits is 444528, while the sum is 49.

The spelling of 21717294709 in words is "twenty-one billion, seven hundred seventeen million, two hundred ninety-four thousand, seven hundred nine".