2166505651 has 8 divisors (see below), whose sum is σ = 2195716464. Its totient is φ = 2137447200.

The previous prime is 2166505633. The next prime is 2166505667. The reversal of 2166505651 is 1565056612.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2166505651 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 2166505651.

It is not an unprimeable number, because it can be changed into a prime (2166505681) 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, 9316 + ... + 66481.

It is an arithmetic number, because the mean of its divisors is an integer number (274464558).

Almost surely, 2^2166505651 is an apocalyptic number.

2166505651 is a deficient number, since it is larger than the sum of its proper divisors (29210813).

2166505651 is a wasteful number, since it uses less digits than its factorization.

2166505651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76181.

The product of its (nonzero) digits is 54000, while the sum is 37.

The square root of 2166505651 is about 46545.7371947206. The cubic root of 2166505651 is about 1293.9572910757.

The spelling of 2166505651 in words is "two billion, one hundred sixty-six million, five hundred five thousand, six hundred fifty-one".