25216646400 has 324 divisors, whose sum is σ = 98353600800. Its totient is φ = 6112972800.

The previous prime is 25216646381. The next prime is 25216646453. The reversal of 25216646400 is 464661252.

25216646400 is a `hidden beast` number, since 2 + 5 + 2 + 1 + 6 + 6 + 4 + 640 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 613701 + ... + 653499.

Almost surely, 2^25216646400 is an apocalyptic number.

25216646400 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 25216646400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49176800400).

25216646400 is an abundant number, since it is smaller than the sum of its proper divisors (73136954400).

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

25216646400 is a wasteful number, since it uses less digits than its factorization.

25216646400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39842 (or 39820 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 25216646400 in words is "twenty-five billion, two hundred sixteen million, six hundred forty-six thousand, four hundred".