2666399616 has 48 divisors (see below), whose sum is σ = 7672845960. Its totient is φ = 888799488.

The previous prime is 2666399611. The next prime is 2666399647. The reversal of 2666399616 is 6169936662.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2666399611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1156140 + ... + 1158443.

Almost surely, 2^2666399616 is an apocalyptic number.

It is an amenable number.

2666399616 is an abundant number, since it is smaller than the sum of its proper divisors (5006446344).

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

2666399616 is a wasteful number, since it uses less digits than its factorization.

2666399616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2314603 (or 2314588 counting only the distinct ones).

The product of its digits is 3779136, while the sum is 54.

The square root of 2666399616 is about 51637.1921777317. The cubic root of 2666399616 is about 1386.6762565083.

The spelling of 2666399616 in words is "two billion, six hundred sixty-six million, three hundred ninety-nine thousand, six hundred sixteen".