2660581640 has 64 divisors (see below), whose sum is σ = 6138063360. Its totient is φ = 1037436160.

The previous prime is 2660581639. The next prime is 2660581657. The reversal of 2660581640 is 461850662.

It is a junction number, because it is equal to n+sod(n) for n = 2660581594 and 2660581603.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 491750 + ... + 497130.

It is an arithmetic number, because the mean of its divisors is an integer number (95907240).

Almost surely, 2^2660581640 is an apocalyptic number.

2660581640 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 2660581640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3069031680).

2660581640 is an abundant number, since it is smaller than the sum of its proper divisors (3477481720).

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

2660581640 is a wasteful number, since it uses less digits than its factorization.

2660581640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5702 (or 5698 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 2660581640 is about 51580.8262826411. The cubic root of 2660581640 is about 1385.6669649257. Note that the first 3 decimals are identical.

The spelling of 2660581640 in words is "two billion, six hundred sixty million, five hundred eighty-one thousand, six hundred forty".