25420691660 has 192 divisors, whose sum is σ = 70636769280. Its totient is φ = 7459153920.

The previous prime is 25420691657. The next prime is 25420691671. The reversal of 25420691660 is 6619602452.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1617440 + ... + 1633080.

It is an arithmetic number, because the mean of its divisors is an integer number (367899840).

Almost surely, 2^25420691660 is an apocalyptic number.

25420691660 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 25420691660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35318384640).

25420691660 is an abundant number, since it is smaller than the sum of its proper divisors (45216077620).

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

25420691660 is a wasteful number, since it uses less digits than its factorization.

25420691660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15736 (or 15734 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 41.

The spelling of 25420691660 in words is "twenty-five billion, four hundred twenty million, six hundred ninety-one thousand, six hundred sixty".