21611764766717 has 8 divisors (see below), whose sum is σ = 22645764069120. Its totient is φ = 20585628577360.

The previous prime is 21611764766689. The next prime is 21611764766759. The reversal of 21611764766717 is 71766746711612.

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

It is a cyclic number.

It is not a de Polignac number, because 21611764766717 - 2¹⁶ = 21611764701181 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21611764766717.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21611764766797) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1965772634 + ... + 1965783627.

It is an arithmetic number, because the mean of its divisors is an integer number (2830720508640).

Almost surely, 2^{21611764766717} is an apocalyptic number.

It is an amenable number.

21611764766717 is a deficient number, since it is larger than the sum of its proper divisors (1033999302403).

21611764766717 is a wasteful number, since it uses less digits than its factorization.

21611764766717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3931556523.

The product of its digits is 24893568, while the sum is 62.

The spelling of 21611764766717 in words is "twenty-one trillion, six hundred eleven billion, seven hundred sixty-four million, seven hundred sixty-six thousand, seven hundred seventeen".