643525231 has 8 divisors (see below), whose sum is σ = 685971200. Its totient is φ = 601936920.

The previous prime is 643525219. The next prime is 643525247. The reversal of 643525231 is 132525346.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643525231 - 2⁵ = 643525199 is a prime.

It is a super-2 number, since 2×643525231² = 828249445867206722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643525193 and 643525202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643525291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212865 + ... + 215866.

It is an arithmetic number, because the mean of its divisors is an integer number (85746400).

Almost surely, 2^643525231 is an apocalyptic number.

643525231 is a deficient number, since it is larger than the sum of its proper divisors (42445969).

643525231 is a wasteful number, since it uses less digits than its factorization.

643525231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428829.

The product of its digits is 21600, while the sum is 31.

The square root of 643525231 is about 25367.7990964924. The cubic root of 643525231 is about 863.3532463948.

The spelling of 643525231 in words is "six hundred forty-three million, five hundred twenty-five thousand, two hundred thirty-one".