2551664640 has 416 divisors, whose sum is σ = 9907833600. Its totient is φ = 547356672.

The previous prime is 2551664573. The next prime is 2551664651. The reversal of 2551664640 is 464661552.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7311186 + ... + 7311534.

Almost surely, 2^2551664640 is an apocalyptic number.

2551664640 is a gapful number since it is divisible by the number (20) 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 2551664640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4953916800).

2551664640 is an abundant number, since it is smaller than the sum of its proper divisors (7356168960).

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

2551664640 is a wasteful number, since it uses less digits than its factorization.

2551664640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 383 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 39.

The square root of 2551664640 is about 50514.0043948210. The cubic root of 2551664640 is about 1366.4944278940.

The spelling of 2551664640 in words is "two billion, five hundred fifty-one million, six hundred sixty-four thousand, six hundred forty".