642794728 has 16 divisors (see below), whose sum is σ = 1211976000. Its totient is φ = 319601136.

The previous prime is 642794723. The next prime is 642794729. The reversal of 642794728 is 827497246.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (642794723) 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 3 ways as a sum of consecutive naturals, for example, 223008 + ... + 225871.

It is an arithmetic number, because the mean of its divisors is an integer number (75748500).

Almost surely, 2^642794728 is an apocalyptic number.

It is an amenable number.

642794728 is a deficient number, since it is larger than the sum of its proper divisors (569181272).

642794728 is a wasteful number, since it uses less digits than its factorization.

642794728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449064 (or 449060 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 49.

The square root of 642794728 is about 25353.3967743969. The cubic root of 642794728 is about 863.0264418407.

The spelling of 642794728 in words is "six hundred forty-two million, seven hundred ninety-four thousand, seven hundred twenty-eight".