643895006525 has 6 divisors (see below), whose sum is σ = 798429808122. Its totient is φ = 515116005200.

The previous prime is 643895006507. The next prime is 643895006527. The reversal of 643895006525 is 525600598346.

643895006525 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 106878647929 + 537016358596 = 326923^2 + 732814^2 .

It is not a de Polignac number, because 643895006525 - 2²⁸ = 643626571069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643895006527) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12877900106 + ... + 12877900155.

It is an arithmetic number, because the mean of its divisors is an integer number (133071634687).

Almost surely, 2^643895006525 is an apocalyptic number.

It is an amenable number.

643895006525 is a deficient number, since it is larger than the sum of its proper divisors (154534801597).

643895006525 is a wasteful number, since it uses less digits than its factorization.

643895006525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25755800271 (or 25755800266 counting only the distinct ones).

The product of its (nonzero) digits is 7776000, while the sum is 53.

The spelling of 643895006525 in words is "six hundred forty-three billion, eight hundred ninety-five million, six thousand, five hundred twenty-five".