642131340640 has 48 divisors (see below), whose sum is σ = 1520491119840. Its totient is φ = 256267422720.

The previous prime is 642131340607. The next prime is 642131340647. The reversal of 642131340640 is 46043131246.

It is a junction number, because it is equal to n+sod(n) for n = 642131340596 and 642131340605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642131340647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4500741 + ... + 4641220.

It is an arithmetic number, because the mean of its divisors is an integer number (31676898330).

Almost surely, 2^642131340640 is an apocalyptic number.

It is an amenable number.

642131340640 is an abundant number, since it is smaller than the sum of its proper divisors (878359779200).

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

642131340640 is a wasteful number, since it uses less digits than its factorization.

642131340640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9142415 (or 9142407 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

Adding to 642131340640 its reverse (46043131246), we get a palindrome (688174471886).

The spelling of 642131340640 in words is "six hundred forty-two billion, one hundred thirty-one million, three hundred forty thousand, six hundred forty".