2565401780 has 12 divisors (see below), whose sum is σ = 5387343780. Its totient is φ = 1026160704.

The previous prime is 2565401753. The next prime is 2565401789. The reversal of 2565401780 is 871045652.

2565401780 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 1629898384 + 935503396 = 40372^2 + 30586^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565401789) 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, 64135025 + ... + 64135064.

It is an arithmetic number, because the mean of its divisors is an integer number (448945315).

Almost surely, 2^2565401780 is an apocalyptic number.

2565401780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2565401780 is an abundant number, since it is smaller than the sum of its proper divisors (2821942000).

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

2565401780 is a wasteful number, since it uses less digits than its factorization.

2565401780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128270098 (or 128270096 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 38.

The square root of 2565401780 is about 50649.7954586196. The cubic root of 2565401780 is about 1368.9422599068.

The spelling of 2565401780 in words is "two billion, five hundred sixty-five million, four hundred one thousand, seven hundred eighty".