641787 has 4 divisors (see below), whose sum is σ = 855720. Its totient is φ = 427856.

The previous prime is 641761. The next prime is 641789. The reversal of 641787 is 787146.

641787 is digitally balanced in base 7, 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 641787 - 2¹¹ = 639739 is a prime.

It is a D-number.

641787 is strictly pandigital in base 7.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 641787.

It is not an unprimeable number, because it can be changed into a prime (641789) 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, 106962 + ... + 106967.

It is an arithmetic number, because the mean of its divisors is an integer number (213930).

2⁶⁴¹⁷⁸⁷ is an apocalyptic number.

641787 is a deficient number, since it is larger than the sum of its proper divisors (213933).

641787 is a wasteful number, since it uses less digits than its factorization.

641787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213932.

The product of its digits is 9408, while the sum is 33.

The square root of 641787 is about 801.1160964554. The cubic root of 641787 is about 86.2575208733.

The spelling of 641787 in words is "six hundred forty-one thousand, seven hundred eighty-seven".