643541197825 has 24 divisors (see below), whose sum is σ = 799379193600. Its totient is φ = 513938208960.

The previous prime is 643541197801. The next prime is 643541197847. The reversal of 643541197825 is 528791145346.

It is not a de Polignac number, because 643541197825 - 2²³ = 643532809217 is a prime.

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36433846 + ... + 36451504.

It is an arithmetic number, because the mean of its divisors is an integer number (33307466400).

Almost surely, 2^643541197825 is an apocalyptic number.

It is an amenable number.

643541197825 is a deficient number, since it is larger than the sum of its proper divisors (155837995775).

643541197825 is a wasteful number, since it uses less digits than its factorization.

643541197825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20121 (or 20116 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 55.

The spelling of 643541197825 in words is "six hundred forty-three billion, five hundred forty-one million, one hundred ninety-seven thousand, eight hundred twenty-five".