642464450881 has 8 divisors (see below), whose sum is σ = 706662628128. Its totient is φ = 584058590500.

The previous prime is 642464450869. The next prime is 642464450921. The reversal of 642464450881 is 188054464246.

It is not a de Polignac number, because 642464450881 - 2³¹ = 640316967233 is a prime.

It is a super-2 number, since 2×642464450881² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642464450981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241345195 + ... + 241347856.

It is an arithmetic number, because the mean of its divisors is an integer number (88332828516).

Almost surely, 2^642464450881 is an apocalyptic number.

It is an amenable number.

642464450881 is a deficient number, since it is larger than the sum of its proper divisors (64198177247).

642464450881 is an equidigital number, since it uses as much as digits as its factorization.

642464450881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482693084 (or 482693062 counting only the distinct ones).

The product of its (nonzero) digits is 5898240, while the sum is 52.

The spelling of 642464450881 in words is "six hundred forty-two billion, four hundred sixty-four million, four hundred fifty thousand, eight hundred eighty-one".