643111401 has 4 divisors (see below), whose sum is σ = 857481872. Its totient is φ = 428740932.

The previous prime is 643111351. The next prime is 643111423. The reversal of 643111401 is 104111346.

643111401 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 643111401 - 2¹⁴ = 643095017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643111451) 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, 107185231 + ... + 107185236.

It is an arithmetic number, because the mean of its divisors is an integer number (214370468).

Almost surely, 2^643111401 is an apocalyptic number.

It is an amenable number.

643111401 is a deficient number, since it is larger than the sum of its proper divisors (214370471).

643111401 is a wasteful number, since it uses less digits than its factorization.

643111401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214370470.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 643111401 is about 25359.6411843701. The cubic root of 643111401 is about 863.1681419786.

Adding to 643111401 its reverse (104111346), we get a palindrome (747222747).

The spelling of 643111401 in words is "six hundred forty-three million, one hundred eleven thousand, four hundred one".