21717256627 has 16 divisors (see below), whose sum is σ = 25188081408. Its totient is φ = 18528246880.

The previous prime is 21717256621. The next prime is 21717256663. The reversal of 21717256627 is 72665271712.

It is not a de Polignac number, because 21717256627 - 2¹¹ = 21717254579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21717256621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 796393 + ... + 823210.

It is an arithmetic number, because the mean of its divisors is an integer number (1574255088).

Almost surely, 2^21717256627 is an apocalyptic number.

21717256627 is a deficient number, since it is larger than the sum of its proper divisors (3470824781).

21717256627 is a wasteful number, since it uses less digits than its factorization.

21717256627 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1619690.

The product of its digits is 493920, while the sum is 46.

The spelling of 21717256627 in words is "twenty-one billion, seven hundred seventeen million, two hundred fifty-six thousand, six hundred twenty-seven".