2666440644 has 36 divisors (see below), whose sum is σ = 7237483344. Its totient is φ = 761840016.

The previous prime is 2666440573. The next prime is 2666440709. The reversal of 2666440644 is 4460446662.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 2666440596 and 2666440605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2266794 + ... + 2267969.

It is an arithmetic number, because the mean of its divisors is an integer number (201041204).

Almost surely, 2^2666440644 is an apocalyptic number.

It is an amenable number.

2666440644 is an abundant number, since it is smaller than the sum of its proper divisors (4571042700).

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

2666440644 is a wasteful number, since it uses less digits than its factorization.

2666440644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4534784 (or 4534775 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 42.

The square root of 2666440644 is about 51637.5894479981. The cubic root of 2666440644 is about 1386.6833687533.

The spelling of 2666440644 in words is "two billion, six hundred sixty-six million, four hundred forty thousand, six hundred forty-four".