642758022818 has 18 divisors (see below), whose sum is σ = 1017585933201. Its totient is φ = 304454122344.

The previous prime is 642758022773. The next prime is 642758022859. The reversal of 642758022818 is 818220857246.

It is a happy number.

642758022818 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 449507225209 + 193250797609 = 670453^2 + 439603^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=566903.

It is a super-2 number, since 2×642758022818² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 642758022818.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 21527396 + ... + 21557232.

Almost surely, 2^642758022818 is an apocalyptic number.

642758022818 is a deficient number, since it is larger than the sum of its proper divisors (374827910383).

642758022818 is an frugal number, since it uses more digits than its factorization.

642758022818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59714 (or 29858 counting only the distinct ones).

The product of its (nonzero) digits is 3440640, while the sum is 53.

The spelling of 642758022818 in words is "six hundred forty-two billion, seven hundred fifty-eight million, twenty-two thousand, eight hundred eighteen".