687942720 has 224 divisors, whose sum is σ = 2459370240. Its totient is φ = 183264768.

The previous prime is 687942707. The next prime is 687942737. The reversal of 687942720 is 27249786.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 699349 + ... + 700331.

Almost surely, 2^687942720 is an apocalyptic number.

687942720 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 687942720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1229685120).

687942720 is an abundant number, since it is smaller than the sum of its proper divisors (1771427520).

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

687942720 is an frugal number, since it uses more digits than its factorization.

687942720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1021 (or 993 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 687942720 is about 26228.6621847169. The cubic root of 687942720 is about 882.7764923701.

The spelling of 687942720 in words is "six hundred eighty-seven million, nine hundred forty-two thousand, seven hundred twenty".