642999268836 has 72 divisors (see below), whose sum is σ = 1665743376024. Its totient is φ = 209012367360.

The previous prime is 642999268799. The next prime is 642999268913. The reversal of 642999268836 is 638862999246.

642999268836 is a `hidden beast` number, since 6 + 429 + 9 + 92 + 6 + 88 + 36 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 134923982400 + 508075286436 = 367320^2 + 712794^2 .

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 3259120 + ... + 3450776.

It is an arithmetic number, because the mean of its divisors is an integer number (23135324667).

Almost surely, 2^642999268836 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 642999268836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (832871688012).

642999268836 is an abundant number, since it is smaller than the sum of its proper divisors (1022744107188).

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

642999268836 is a wasteful number, since it uses less digits than its factorization.

642999268836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193981 (or 193976 counting only the distinct ones).

The product of its digits is 483729408, while the sum is 72.

The spelling of 642999268836 in words is "six hundred forty-two billion, nine hundred ninety-nine million, two hundred sixty-eight thousand, eight hundred thirty-six".