685998720 has 384 divisors, whose sum is σ = 2686582080. Its totient is φ = 165888000.

The previous prime is 685998707. The next prime is 685998751. The reversal of 685998720 is 27899586.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1710520 + ... + 1710920.

Almost surely, 2^685998720 is an apocalyptic number.

685998720 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 685998720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1343291040).

685998720 is an abundant number, since it is smaller than the sum of its proper divisors (2000583360).

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

685998720 is a wasteful number, since it uses less digits than its factorization.

685998720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The square root of 685998720 is about 26191.5772720926. The cubic root of 685998720 is about 881.9441863890.

The spelling of 685998720 in words is "six hundred eighty-five million, nine hundred ninety-eight thousand, seven hundred twenty".