25628617728 has 440 divisors, whose sum is σ = 89904436512. Its totient is φ = 7118585856.

The previous prime is 25628617711. The next prime is 25628617753. The reversal of 25628617728 is 82771682652.

25628617728 is a `hidden beast` number, since 2 + 5 + 628 + 6 + 1 + 7 + 7 + 2 + 8 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 21481900 + ... + 21483092.

Almost surely, 2^25628617728 is an apocalyptic number.

25628617728 is a gapful number since it is divisible by the number (28) 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 25628617728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44952218256).

25628617728 is an abundant number, since it is smaller than the sum of its proper divisors (64275818784).

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

25628617728 is a wasteful number, since it uses less digits than its factorization.

25628617728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269 (or 1242 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The spelling of 25628617728 in words is "twenty-five billion, six hundred twenty-eight million, six hundred seventeen thousand, seven hundred twenty-eight".