643289458978 has 8 divisors (see below), whose sum is σ = 991013490972. Its totient is φ = 312951628656.

The previous prime is 643289458969. The next prime is 643289458997. The reversal of 643289458978 is 879854982346.

It can be written as a sum of positive squares in 2 ways, for example, as 641317477329 + 1971981649 = 800823^2 + 44407^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 643289458978.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4346550325 + ... + 4346550472.

Almost surely, 2^643289458978 is an apocalyptic number.

643289458978 is a deficient number, since it is larger than the sum of its proper divisors (347724031994).

643289458978 is a wasteful number, since it uses less digits than its factorization.

643289458978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8693100836.

The product of its digits is 836075520, while the sum is 73.

The spelling of 643289458978 in words is "six hundred forty-three billion, two hundred eighty-nine million, four hundred fifty-eight thousand, nine hundred seventy-eight".