643151071 has 2 divisors, whose sum is σ = 643151072. Its totient is φ = 643151070.

The previous prime is 643151063. The next prime is 643151111. The reversal of 643151071 is 170151346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643151071 - 2³ = 643151063 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643151011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321575535 + 321575536.

It is an arithmetic number, because the mean of its divisors is an integer number (321575536).

Almost surely, 2^643151071 is an apocalyptic number.

643151071 is a deficient number, since it is larger than the sum of its proper divisors (1).

643151071 is an equidigital number, since it uses as much as digits as its factorization.

643151071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 643151071 is about 25360.4233205994. The cubic root of 643151071 is about 863.1858896431.

The spelling of 643151071 in words is "six hundred forty-three million, one hundred fifty-one thousand, seventy-one".