25891397280 has 672 divisors, whose sum is σ = 110394748800. Its totient is φ = 5603198976.

The previous prime is 25891397251. The next prime is 25891397281. The reversal of 25891397280 is 8279319852.

25891397280 is a `hidden beast` number, since 2 + 589 + 1 + 39 + 7 + 28 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×25891397280² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25891397281) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 15512286 + ... + 15513954.

It is an arithmetic number, because the mean of its divisors is an integer number (164277900).

Almost surely, 2^25891397280 is an apocalyptic number.

25891397280 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 25891397280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55197374400).

25891397280 is an abundant number, since it is smaller than the sum of its proper divisors (84503351520).

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

25891397280 is a wasteful number, since it uses less digits than its factorization.

25891397280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1728 (or 1705 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The spelling of 25891397280 in words is "twenty-five billion, eight hundred ninety-one million, three hundred ninety-seven thousand, two hundred eighty".