25644003660 has 288 divisors, whose sum is σ = 87639552000. Its totient is φ = 6014891520.

The previous prime is 25644003607. The next prime is 25644003667. The reversal of 25644003660 is 6630044652.

25644003660 is a `hidden beast` number, since 2 + 5 + 644 + 0 + 0 + 3 + 6 + 6 + 0 = 666.

It is a super-2 number, since 2×25644003660² (a number of 22 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 (25644003667) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 14577861 + ... + 14579619.

It is an arithmetic number, because the mean of its divisors is an integer number (304304000).

Almost surely, 2^25644003660 is an apocalyptic number.

25644003660 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 25644003660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43819776000).

25644003660 is an abundant number, since it is smaller than the sum of its proper divisors (61995548340).

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

25644003660 is a wasteful number, since it uses less digits than its factorization.

25644003660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2021 (or 2016 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The spelling of 25644003660 in words is "twenty-five billion, six hundred forty-four million, three thousand, six hundred sixty".