2566561640 has 32 divisors (see below), whose sum is σ = 5909064480. Its totient is φ = 1002748992.

The previous prime is 2566561631. The next prime is 2566561643. The reversal of 2566561640 is 461656652.

It is not an unprimeable number, because it can be changed into a prime (2566561643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 744374 + ... + 747813.

It is an arithmetic number, because the mean of its divisors is an integer number (184658265).

Almost surely, 2^2566561640 is an apocalyptic number.

2566561640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2566561640 is an abundant number, since it is smaller than the sum of its proper divisors (3342502840).

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

2566561640 is a wasteful number, since it uses less digits than its factorization.

2566561640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1492241 (or 1492237 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 41.

The square root of 2566561640 is about 50661.2439641981. The cubic root of 2566561640 is about 1369.1485358665.

The spelling of 2566561640 in words is "two billion, five hundred sixty-six million, five hundred sixty-one thousand, six hundred forty".