2565117681 has 16 divisors (see below), whose sum is σ = 3938592768. Its totient is φ = 1454590800.

The previous prime is 2565117671. The next prime is 2565117707. The reversal of 2565117681 is 1867115652.

2565117681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2565117681 - 2⁶ = 2565117617 is a prime.

It is a super-2 number, since 2×2565117681² = 13159657434757635522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2565117631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 463465 + ... + 468966.

It is an arithmetic number, because the mean of its divisors is an integer number (246162048).

Almost surely, 2^2565117681 is an apocalyptic number.

2565117681 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2565117681 is a deficient number, since it is larger than the sum of its proper divisors (1373475087).

2565117681 is a wasteful number, since it uses less digits than its factorization.

2565117681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 932572.

The product of its digits is 100800, while the sum is 42.

The square root of 2565117681 is about 50646.9908385483. The cubic root of 2565117681 is about 1368.8917246798.

The spelling of 2565117681 in words is "two billion, five hundred sixty-five million, one hundred seventeen thousand, six hundred eighty-one".