642313728 has 120 divisors (see below), whose sum is σ = 2118690288. Its totient is φ = 183508992.

The previous prime is 642313691. The next prime is 642313729. The reversal of 642313728 is 827313246.

It is a happy number.

642313728 is a `hidden beast` number, since 642 + 3 + 1 + 3 + 7 + 2 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 642313692 and 642313701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642313729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22300 + ... + 42212.

Almost surely, 2^642313728 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 642313728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1059345144).

642313728 is an abundant number, since it is smaller than the sum of its proper divisors (1476376560).

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

642313728 is a wasteful number, since it uses less digits than its factorization.

642313728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19944 (or 19925 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 642313728 is about 25343.9090907460. The cubic root of 642313728 is about 862.8111220367.

The spelling of 642313728 in words is "six hundred forty-two million, three hundred thirteen thousand, seven hundred twenty-eight".