25985691648 has 520 divisors, whose sum is σ = 90579616512. Its totient is φ = 7269875712.

The previous prime is 25985691643. The next prime is 25985691653. The reversal of 25985691648 is 84619658952.

25985691648 is a `hidden beast` number, since 2 + 5 + 9 + 8 + 569 + 1 + 64 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (25985691643) and next prime (25985691653).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (25985691643) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 155602861 + ... + 155603027.

Almost surely, 2^25985691648 is an apocalyptic number.

25985691648 is a gapful number since it is divisible by the number (28) 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 25985691648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45289808256).

25985691648 is an abundant number, since it is smaller than the sum of its proper divisors (64593924864).

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

25985691648 is an equidigital number, since it uses as much as digits as its factorization.

25985691648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277 (or 246 counting only the distinct ones).

The product of its digits is 37324800, while the sum is 63.

The spelling of 25985691648 in words is "twenty-five billion, nine hundred eighty-five million, six hundred ninety-one thousand, six hundred forty-eight".