687923820 has 48 divisors (see below), whose sum is σ = 2140209120. Its totient is φ = 183446208.

The previous prime is 687923771. The next prime is 687923833. The reversal of 687923820 is 28329786.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 636427 + ... + 637506.

It is an arithmetic number, because the mean of its divisors is an integer number (44587690).

Almost surely, 2^687923820 is an apocalyptic number.

687923820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

687923820 is an abundant number, since it is smaller than the sum of its proper divisors (1452285300).

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

687923820 is a wasteful number, since it uses less digits than its factorization.

687923820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1273951 (or 1273943 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 687923820 is about 26228.3018893713. The cubic root of 687923820 is about 882.7684080592.

The spelling of 687923820 in words is "six hundred eighty-seven million, nine hundred twenty-three thousand, eight hundred twenty".