25491421872 has 200 divisors, whose sum is σ = 85912063776. Its totient is φ = 7145708544.

The previous prime is 25491421871. The next prime is 25491421897. The reversal of 25491421872 is 27812419452.

25491421872 is a `hidden beast` number, since 2 + 549 + 1 + 4 + 21 + 87 + 2 = 666.

It is not an unprimeable number, because it can be changed into a prime (25491421871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 454308 + ... + 507324.

Almost surely, 2^25491421872 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 25491421872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42956031888).

25491421872 is an abundant number, since it is smaller than the sum of its proper divisors (60420641904).

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

25491421872 is a wasteful number, since it uses less digits than its factorization.

25491421872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53097 (or 53082 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The spelling of 25491421872 in words is "twenty-five billion, four hundred ninety-one million, four hundred twenty-one thousand, eight hundred seventy-two".