25681905408 has 144 divisors (see below), whose sum is σ = 72191463680. Its totient is φ = 8082726912.

The previous prime is 25681905397. The next prime is 25681905437. The reversal of 25681905408 is 80450918652.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4564485 + ... + 4570107.

Almost surely, 2^25681905408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25681905408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36095731840).

25681905408 is an abundant number, since it is smaller than the sum of its proper divisors (46509558272).

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

25681905408 is a wasteful number, since it uses less digits than its factorization.

25681905408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5974 (or 5960 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 48.

The spelling of 25681905408 in words is "twenty-five billion, six hundred eighty-one million, nine hundred five thousand, four hundred eight".