684891840 has 224 divisors, whose sum is σ = 2287097280. Its totient is φ = 173408256.

The previous prime is 684891833. The next prime is 684891859. The reversal of 684891840 is 48198486.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 684891840.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2032152 + ... + 2032488.

Almost surely, 2^684891840 is an apocalyptic number.

684891840 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 684891840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1143548640).

684891840 is an abundant number, since it is smaller than the sum of its proper divisors (1602205440).

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

684891840 is a wasteful number, since it uses less digits than its factorization.

684891840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459 (or 449 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 48.

The square root of 684891840 is about 26170.4382844461. The cubic root of 684891840 is about 881.4695830260.

The spelling of 684891840 in words is "six hundred eighty-four million, eight hundred ninety-one thousand, eight hundred forty".