687669720 has 192 divisors, whose sum is σ = 2228083200. Its totient is φ = 169728000.

The previous prime is 687669713. The next prime is 687669727. The reversal of 687669720 is 27966786.

It is an interprime number because it is at equal distance from previous prime (687669713) and next prime (687669727).

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687669727) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2739595 + ... + 2739845.

It is an arithmetic number, because the mean of its divisors is an integer number (11604600).

Almost surely, 2^687669720 is an apocalyptic number.

687669720 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 687669720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1114041600).

687669720 is an abundant number, since it is smaller than the sum of its proper divisors (1540413480).

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

687669720 is a wasteful number, since it uses less digits than its factorization.

687669720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 51.

The square root of 687669720 is about 26223.4574379505. The cubic root of 687669720 is about 882.6597046099.

The spelling of 687669720 in words is "six hundred eighty-seven million, six hundred sixty-nine thousand, seven hundred twenty".