641780823 has 8 divisors (see below), whose sum is σ = 855853936. Its totient is φ = 427780800.

The previous prime is 641780813. The next prime is 641780827. The reversal of 641780823 is 328087146.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 641780823 - 2⁸ = 641780567 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 (641780827) 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 7 ways as a sum of consecutive naturals, for example, 7353 + ... + 36573.

It is an arithmetic number, because the mean of its divisors is an integer number (106981742).

Almost surely, 2^641780823 is an apocalyptic number.

641780823 is a deficient number, since it is larger than the sum of its proper divisors (214073113).

641780823 is a wasteful number, since it uses less digits than its factorization.

641780823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36545.

The product of its (nonzero) digits is 64512, while the sum is 39.

The square root of 641780823 is about 25333.3934363322. The cubic root of 641780823 is about 862.5724413845.

The spelling of 641780823 in words is "six hundred forty-one million, seven hundred eighty thousand, eight hundred twenty-three".