2171611666511 has 24 divisors (see below), whose sum is σ = 2730984378480. Its totient is φ = 1715754120192.

The previous prime is 2171611666463. The next prime is 2171611666517. The reversal of 2171611666511 is 1156661161712.

It is a de Polignac number, because none of the positive numbers 2^k-2171611666511 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2171611666517) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31486610 + ... + 31555503.

It is an arithmetic number, because the mean of its divisors is an integer number (113791015770).

Almost surely, 2^{2171611666511} is an apocalyptic number.

2171611666511 is a deficient number, since it is larger than the sum of its proper divisors (559372711969).

2171611666511 is a wasteful number, since it uses less digits than its factorization.

2171611666511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63042183 (or 63042176 counting only the distinct ones).

The product of its digits is 90720, while the sum is 44.

The spelling of 2171611666511 in words is "two trillion, one hundred seventy-one billion, six hundred eleven million, six hundred sixty-six thousand, five hundred eleven".