643434945 has 16 divisors (see below), whose sum is σ = 1030760640. Its totient is φ = 342743744.

The previous prime is 643434937. The next prime is 643435003. The reversal of 643434945 is 549434346.

It is a cyclic number.

It is not a de Polignac number, because 643434945 - 2³ = 643434937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643434897 and 643434906.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13530 + ... + 38339.

It is an arithmetic number, because the mean of its divisors is an integer number (64422540).

Almost surely, 2^643434945 is an apocalyptic number.

It is an amenable number.

643434945 is a deficient number, since it is larger than the sum of its proper divisors (387325695).

643434945 is a wasteful number, since it uses less digits than its factorization.

643434945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52704.

The product of its digits is 622080, while the sum is 42.

The square root of 643434945 is about 25366.0194945916. The cubic root of 643434945 is about 863.3128686168.

The spelling of 643434945 in words is "six hundred forty-three million, four hundred thirty-four thousand, nine hundred forty-five".