641567 has 4 divisors (see below), whose sum is σ = 663720. Its totient is φ = 619416.

The previous prime is 641551. The next prime is 641579. The reversal of 641567 is 765146.

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 641567 - 2⁴ = 641551 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 22123 = 641567 / (6 + 4 + 1 + 5 + 6 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11033 + ... + 11090.

It is an arithmetic number, because the mean of its divisors is an integer number (165930).

2⁶⁴¹⁵⁶⁷ is an apocalyptic number.

641567 is a deficient number, since it is larger than the sum of its proper divisors (22153).

641567 is a wasteful number, since it uses less digits than its factorization.

641567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22152.

The product of its digits is 5040, while the sum is 29.

The square root of 641567 is about 800.9787762482. The cubic root of 641567 is about 86.2476635928.

The spelling of 641567 in words is "six hundred forty-one thousand, five hundred sixty-seven".