2565540861840 has 480 divisors, whose sum is σ = 10026608256000. Its totient is φ = 601884518400.

The previous prime is 2565540861799. The next prime is 2565540861869. The reversal of 2565540861840 is 481680455652.

2565540861840 is a `hidden beast` number, since 2 + 5 + 6 + 5 + 540 + 86 + 18 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7943836 + ... + 8260484.

It is an arithmetic number, because the mean of its divisors is an integer number (20888767200).

Almost surely, 2^{2565540861840} is an apocalyptic number.

2565540861840 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 2565540861840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5013304128000).

2565540861840 is an abundant number, since it is smaller than the sum of its proper divisors (7461067394160).

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

2565540861840 is a wasteful number, since it uses less digits than its factorization.

2565540861840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316724 (or 316701 counting only the distinct ones).

The product of its (nonzero) digits is 9216000, while the sum is 54.

The spelling of 2565540861840 in words is "two trillion, five hundred sixty-five billion, five hundred forty million, eight hundred sixty-one thousand, eight hundred forty".