2556666767440 has 20 divisors (see below), whose sum is σ = 5944250234484. Its totient is φ = 1022666706944.

The previous prime is 2556666767437. The next prime is 2556666767441. The reversal of 2556666767440 is 447676666552.

It can be written as a sum of positive squares in 2 ways, for example, as 1491593230864 + 1065073536576 = 1221308^2 + 1032024^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2556666767441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15979167217 + ... + 15979167376.

Almost surely, 2^{2556666767440} is an apocalyptic number.

2556666767440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2556666767440 is an abundant number, since it is smaller than the sum of its proper divisors (3387583467044).

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

2556666767440 is a wasteful number, since it uses less digits than its factorization.

2556666767440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31958334606 (or 31958334600 counting only the distinct ones).

The product of its (nonzero) digits is 304819200, while the sum is 64.

The spelling of 2556666767440 in words is "two trillion, five hundred fifty-six billion, six hundred sixty-six million, seven hundred sixty-seven thousand, four hundred forty".