643427697 has 32 divisors (see below), whose sum is σ = 959422464. Its totient is φ = 380217600.

The previous prime is 643427693. The next prime is 643427699. The reversal of 643427697 is 796724346.

It is not a de Polignac number, because 643427697 - 2² = 643427693 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643427693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 522072 + ... + 523302.

It is an arithmetic number, because the mean of its divisors is an integer number (29981952).

Almost surely, 2^643427697 is an apocalyptic number.

It is an amenable number.

643427697 is a deficient number, since it is larger than the sum of its proper divisors (315994767).

643427697 is a wasteful number, since it uses less digits than its factorization.

643427697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1629.

The product of its digits is 1524096, while the sum is 48.

The square root of 643427697 is about 25365.8766258925. The cubic root of 643427697 is about 863.3096269966.

The spelling of 643427697 in words is "six hundred forty-three million, four hundred twenty-seven thousand, six hundred ninety-seven".