643264858 has 4 divisors (see below), whose sum is σ = 964897290. Its totient is φ = 321632428.

The previous prime is 643264837. The next prime is 643264861. The reversal of 643264858 is 858462346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 594725769 + 48539089 = 24387^2 + 6967^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160816213 + ... + 160816216.

Almost surely, 2^643264858 is an apocalyptic number.

643264858 is a deficient number, since it is larger than the sum of its proper divisors (321632432).

643264858 is a wasteful number, since it uses less digits than its factorization.

643264858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321632431.

The product of its digits is 1105920, while the sum is 46.

The square root of 643264858 is about 25362.6666184769. Note that the first 4 decimals coincide. The cubic root of 643264858 is about 863.2367919093.

The spelling of 643264858 in words is "six hundred forty-three million, two hundred sixty-four thousand, eight hundred fifty-eight".