2561525040420 has 72 divisors (see below), whose sum is σ = 7916562324216. Its totient is φ = 670185165312.

The previous prime is 2561525040383. The next prime is 2561525040427. The reversal of 2561525040420 is 240405251652.

2561525040420 is a `hidden beast` number, since 2 + 5 + 61 + 52 + 504 + 0 + 42 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 50035426596 + 2511489613824 = 223686^2 + 1584768^2 .

It is a super-2 number, since 2×2561525040420² (a number of 26 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (2561525040427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 134242297 + ... + 134261376.

It is an arithmetic number, because the mean of its divisors is an integer number (109952254503).

Almost surely, 2^{2561525040420} is an apocalyptic number.

2561525040420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2561525040420 is an abundant number, since it is smaller than the sum of its proper divisors (5355037283796).

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

2561525040420 is a wasteful number, since it uses less digits than its factorization.

2561525040420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268503741 (or 268503736 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 36.

The spelling of 2561525040420 in words is "two trillion, five hundred sixty-one billion, five hundred twenty-five million, forty thousand, four hundred twenty".