2166372864 has 100 divisors (see below), whose sum is σ = 6466176354. Its totient is φ = 722110464.

The previous prime is 2166372851. The next prime is 2166372869. The reversal of 2166372864 is 4682736612.

2166372864 is a `hidden beast` number, since 2 + 1 + 6 + 637 + 2 + 8 + 6 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1928966400 + 237406464 = 43920^2 + 15408^2 .

It is not an unprimeable number, because it can be changed into a prime (2166372869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 15354 + ... + 67590.

Almost surely, 2^2166372864 is an apocalyptic number.

2166372864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2166372864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3233088177).

2166372864 is an abundant number, since it is smaller than the sum of its proper divisors (4299803490).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2166372864 is an frugal number, since it uses more digits than its factorization.

2166372864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52267 (or 52242 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The square root of 2166372864 is about 46544.3107586738. The cubic root of 2166372864 is about 1293.9308546162.

The spelling of 2166372864 in words is "two billion, one hundred sixty-six million, three hundred seventy-two thousand, eight hundred sixty-four".