644000424525 has 120 divisors (see below), whose sum is σ = 1203562904544. Its totient is φ = 340407100800.

The previous prime is 644000424467. The next prime is 644000424559. The reversal of 644000424525 is 525424000446.

644000424525 is a `hidden beast` number, since 6 + 4 + 400 + 0 + 4 + 245 + 2 + 5 = 666.

644000424525 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644000424525 - 2²¹ = 643998327373 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644000424525.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 393402007 + ... + 393403643.

Almost surely, 2^644000424525 is an apocalyptic number.

It is an amenable number.

644000424525 is a deficient number, since it is larger than the sum of its proper divisors (559562480019).

644000424525 is a wasteful number, since it uses less digits than its factorization.

644000424525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3273 (or 3259 counting only the distinct ones).

The product of its (nonzero) digits is 153600, while the sum is 36.

The spelling of 644000424525 in words is "six hundred forty-four billion, four hundred twenty-four thousand, five hundred twenty-five".