641672820839 has 4 divisors (see below), whose sum is σ = 641677044240. Its totient is φ = 641668597440.

The previous prime is 641672820821. The next prime is 641672820847. The reversal of 641672820839 is 938028276146.

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 641672820839 - 2³² = 637377853543 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 (641672820809) 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, 1874954 + ... + 2190615.

It is an arithmetic number, because the mean of its divisors is an integer number (160419261060).

Almost surely, 2^641672820839 is an apocalyptic number.

641672820839 is a deficient number, since it is larger than the sum of its proper divisors (4223401).

641672820839 is a wasteful number, since it uses less digits than its factorization.

641672820839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4223400.

The product of its (nonzero) digits is 6967296, while the sum is 56.

The spelling of 641672820839 in words is "six hundred forty-one billion, six hundred seventy-two million, eight hundred twenty thousand, eight hundred thirty-nine".