641878111 has 4 divisors (see below), whose sum is σ = 733574992. Its totient is φ = 550181232.

The previous prime is 641878091. The next prime is 641878117. The reversal of 641878111 is 111878146.

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 641878111 - 2⁵ = 641878079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641878117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45848430 + ... + 45848443.

It is an arithmetic number, because the mean of its divisors is an integer number (183393748).

Almost surely, 2^641878111 is an apocalyptic number.

641878111 is a deficient number, since it is larger than the sum of its proper divisors (91696881).

641878111 is an equidigital number, since it uses as much as digits as its factorization.

641878111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91696880.

The product of its digits is 10752, while the sum is 37.

The square root of 641878111 is about 25335.3135169076. The cubic root of 641878111 is about 862.6160251671.

The spelling of 641878111 in words is "six hundred forty-one million, eight hundred seventy-eight thousand, one hundred eleven".