646878292 has 12 divisors (see below), whose sum is σ = 1171072980. Its totient is φ = 312286016.

The previous prime is 646878277. The next prime is 646878299. The reversal of 646878292 is 292878646.

It can be written as a sum of positive squares in 2 ways, for example, as 465006096 + 181872196 = 21564^2 + 13486^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646878299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2788153 + ... + 2788384.

It is an arithmetic number, because the mean of its divisors is an integer number (97589415).

Almost surely, 2^646878292 is an apocalyptic number.

It is an amenable number.

646878292 is a deficient number, since it is larger than the sum of its proper divisors (524194688).

646878292 is a wasteful number, since it uses less digits than its factorization.

646878292 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5576570 (or 5576568 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 52.

The square root of 646878292 is about 25433.8021538267. The cubic root of 646878292 is about 864.8501380927.

The spelling of 646878292 in words is "six hundred forty-six million, eight hundred seventy-eight thousand, two hundred ninety-two".