25661814320 has 20 divisors (see below), whose sum is σ = 59663718480. Its totient is φ = 10264725696.

The previous prime is 25661814317. The next prime is 25661814323. The reversal of 25661814320 is 2341816652.

It is an interprime number because it is at equal distance from previous prime (25661814317) and next prime (25661814323).

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (25661814323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160386260 + ... + 160386419.

It is an arithmetic number, because the mean of its divisors is an integer number (2983185924).

Almost surely, 2^25661814320 is an apocalyptic number.

25661814320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25661814320 is an abundant number, since it is smaller than the sum of its proper divisors (34001904160).

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

25661814320 is a wasteful number, since it uses less digits than its factorization.

25661814320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320772692 (or 320772686 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The spelling of 25661814320 in words is "twenty-five billion, six hundred sixty-one million, eight hundred fourteen thousand, three hundred twenty".