643571231 has 2 divisors, whose sum is σ = 643571232. Its totient is φ = 643571230.

The previous prime is 643571197. The next prime is 643571263. The reversal of 643571231 is 132175346.

It is an a-pointer prime, because the next prime (643571263) can be obtained adding 643571231 to its sum of digits (32).

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643571231 is a prime.

It is a super-2 number, since 2×643571231² = 828367858741710722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643571281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321785615 + 321785616.

It is an arithmetic number, because the mean of its divisors is an integer number (321785616).

Almost surely, 2^643571231 is an apocalyptic number.

643571231 is a deficient number, since it is larger than the sum of its proper divisors (1).

643571231 is an equidigital number, since it uses as much as digits as its factorization.

643571231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 32.

The square root of 643571231 is about 25368.7057415234. The cubic root of 643571231 is about 863.3738170998.

The spelling of 643571231 in words is "six hundred forty-three million, five hundred seventy-one thousand, two hundred thirty-one".