25994672640 has 240 divisors, whose sum is σ = 92463052968. Its totient is φ = 6744342528.

The previous prime is 25994672581. The next prime is 25994672659. The reversal of 25994672640 is 4627649952.

25994672640 is a `hidden beast` number, since 2 + 599 + 4 + 6 + 7 + 2 + 6 + 40 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 19955517696 + 6039154944 = 141264^2 + 77712^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 837234 + ... + 867726.

Almost surely, 2^25994672640 is an apocalyptic number.

25994672640 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 25994672640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46231526484).

25994672640 is an abundant number, since it is smaller than the sum of its proper divisors (66468380328).

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

25994672640 is a wasteful number, since it uses less digits than its factorization.

25994672640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30559 (or 30540 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 54.

The spelling of 25994672640 in words is "twenty-five billion, nine hundred ninety-four million, six hundred seventy-two thousand, six hundred forty".