636625225728 has 252 divisors, whose sum is σ = 1911463522605. Its totient is φ = 211883433984.

The previous prime is 636625225711. The next prime is 636625225741. The reversal of 636625225728 is 827522526636.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

636625225728 is a `hidden beast` number, since 6 + 3 + 6 + 62 + 5 + 2 + 2 + 572 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 587319911424 + 49305314304 = 766368^2 + 222048^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=564192.

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

It is an unprimeable number.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 974923450 + ... + 974924102.

Almost surely, 2^636625225728 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 636625225728

636625225728 is an abundant number, since it is smaller than the sum of its proper divisors (1274838296877).

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

636625225728 is an frugal number, since it uses more digits than its factorization.

636625225728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1346 (or 658 counting only the distinct ones).

The product of its digits is 14515200, while the sum is 54.

The spelling of 636625225728 in words is "six hundred thirty-six billion, six hundred twenty-five million, two hundred twenty-five thousand, seven hundred twenty-eight".