641442604021 has 4 divisors (see below), whose sum is σ = 642216359500. Its totient is φ = 640668848544.

The previous prime is 641442603979. The next prime is 641442604057. The reversal of 641442604021 is 120406244146.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 388347080625 + 253095523396 = 623175^2 + 503086^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641442604021 is a prime.

It is a super-2 number, since 2×641442604021² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641442604091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 386876496 + ... + 386878153.

It is an arithmetic number, because the mean of its divisors is an integer number (160554089875).

Almost surely, 2^641442604021 is an apocalyptic number.

It is an amenable number.

641442604021 is a deficient number, since it is larger than the sum of its proper divisors (773755479).

641442604021 is an equidigital number, since it uses as much as digits as its factorization.

641442604021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773755478.

The product of its (nonzero) digits is 36864, while the sum is 34.

Adding to 641442604021 its reverse (120406244146), we get a palindrome (761848848167).

The spelling of 641442604021 in words is "six hundred forty-one billion, four hundred forty-two million, six hundred four thousand, twenty-one".