684951840 has 144 divisors (see below), whose sum is σ = 2355889536. Its totient is φ = 181209600.

The previous prime is 684951809. The next prime is 684951857. The reversal of 684951840 is 48159486.

It is a tau number, because it is divible by the number of its divisors (144).

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 23 ways as a sum of consecutive naturals, for example, 186825 + ... + 190455.

It is an arithmetic number, because the mean of its divisors is an integer number (16360344).

Almost surely, 2^684951840 is an apocalyptic number.

684951840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684951840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1177944768).

684951840 is an abundant number, since it is smaller than the sum of its proper divisors (1670937696).

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

684951840 is a wasteful number, since it uses less digits than its factorization.

684951840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3783 (or 3772 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 684951840 is about 26171.5845909261. The cubic root of 684951840 is about 881.4953226770.

The spelling of 684951840 in words is "six hundred eighty-four million, nine hundred fifty-one thousand, eight hundred forty".