642944662596 has 72 divisors (see below), whose sum is σ = 1654322482904. Its totient is φ = 210487818240.

The previous prime is 642944662579. The next prime is 642944662597. The reversal of 642944662596 is 695266449246.

642944662596 is a `hidden beast` number, since 6 + 42 + 9 + 446 + 62 + 5 + 96 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 34497861696 + 608446800900 = 185736^2 + 780030^2 .

It is not an unprimeable number, because it can be changed into a prime (642944662597) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1260390 + ... + 1695426.

Almost surely, 2^642944662596 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642944662596, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (827161241452).

642944662596 is an abundant number, since it is smaller than the sum of its proper divisors (1011377820308).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642944662596 is a wasteful number, since it uses less digits than its factorization.

642944662596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435781 (or 435776 counting only the distinct ones).

The product of its digits is 134369280, while the sum is 63.

The spelling of 642944662596 in words is "six hundred forty-two billion, nine hundred forty-four million, six hundred sixty-two thousand, five hundred ninety-six".