2565165440 has 64 divisors (see below), whose sum is σ = 6158164320. Its totient is φ = 1021747200.

The previous prime is 2565165437. The next prime is 2565165443. The reversal of 2565165440 is 445615652.

It is an interprime number because it is at equal distance from previous prime (2565165437) and next prime (2565165443).

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 2565165394 and 2565165403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565165443) 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, 145925 + ... + 162555.

Almost surely, 2^2565165440 is an apocalyptic number.

2565165440 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 2565165440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3079082160).

2565165440 is an abundant number, since it is smaller than the sum of its proper divisors (3592998880).

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

2565165440 is a wasteful number, since it uses less digits than its factorization.

2565165440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16891 (or 16879 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 38.

The square root of 2565165440 is about 50647.4623253722. The cubic root of 2565165440 is about 1368.9002202606.

The spelling of 2565165440 in words is "two billion, five hundred sixty-five million, one hundred sixty-five thousand, four hundred forty".