643485995 has 4 divisors (see below), whose sum is σ = 772183200. Its totient is φ = 514788792.

The previous prime is 643485991. The next prime is 643486001. The reversal of 643485995 is 599584346.

643485995 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 643485995 - 2² = 643485991 is a prime.

It is a super-2 number, since 2×643485995² = 828148451522280050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (643485991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64348595 + ... + 64348604.

It is an arithmetic number, because the mean of its divisors is an integer number (193045800).

Almost surely, 2^643485995 is an apocalyptic number.

643485995 is a deficient number, since it is larger than the sum of its proper divisors (128697205).

643485995 is a wasteful number, since it uses less digits than its factorization.

643485995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128697204.

The product of its digits is 4665600, while the sum is 53.

The square root of 643485995 is about 25367.0257420928. The cubic root of 643485995 is about 863.3356997032.

It can be divided in two parts, 6434 and 85995, that added together give a palindrome (92429).

The spelling of 643485995 in words is "six hundred forty-three million, four hundred eighty-five thousand, nine hundred ninety-five".