25620021520 has 20 divisors (see below), whose sum is σ = 59566550220. Its totient is φ = 10248008576.

The previous prime is 25620021437. The next prime is 25620021523. The reversal of 25620021520 is 2512002652.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14079246336 + 11540775184 = 118656^2 + 107428^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×25620021520² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25620021523) 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, 160125055 + ... + 160125214.

It is an arithmetic number, because the mean of its divisors is an integer number (2978327511).

Almost surely, 2^25620021520 is an apocalyptic number.

25620021520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25620021520 is an abundant number, since it is smaller than the sum of its proper divisors (33946528700).

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

25620021520 is a wasteful number, since it uses less digits than its factorization.

25620021520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320250282 (or 320250276 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The spelling of 25620021520 in words is "twenty-five billion, six hundred twenty million, twenty-one thousand, five hundred twenty".