686782820 has 24 divisors (see below), whose sum is σ = 1443740928. Its totient is φ = 274428000.

The previous prime is 686782777. The next prime is 686782861. The reversal of 686782820 is 28287686.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2495 + ... + 37145.

It is an arithmetic number, because the mean of its divisors is an integer number (60155872).

Almost surely, 2^686782820 is an apocalyptic number.

It is an amenable number.

686782820 is an abundant number, since it is smaller than the sum of its proper divisors (756958108).

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

686782820 is a wasteful number, since it uses less digits than its factorization.

686782820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35651 (or 35649 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 47.

The square root of 686782820 is about 26206.5415497734. The cubic root of 686782820 is about 882.2800806643.

The spelling of 686782820 in words is "six hundred eighty-six million, seven hundred eighty-two thousand, eight hundred twenty".