643504427 has 8 divisors (see below), whose sum is σ = 647220000. Its totient is φ = 639797184.

The previous prime is 643504423. The next prime is 643504447. The reversal of 643504427 is 724405346.

643504427 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 643504427 - 2² = 643504423 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643504423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 213074 + ... + 216072.

It is an arithmetic number, because the mean of its divisors is an integer number (80902500).

Almost surely, 2^643504427 is an apocalyptic number.

643504427 is a deficient number, since it is larger than the sum of its proper divisors (3715573).

643504427 is a wasteful number, since it uses less digits than its factorization.

643504427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4165.

The product of its (nonzero) digits is 80640, while the sum is 35.

The square root of 643504427 is about 25367.3890457808. The cubic root of 643504427 is about 863.3439427480.

The spelling of 643504427 in words is "six hundred forty-three million, five hundred four thousand, four hundred twenty-seven".