688091400 has 144 divisors (see below), whose sum is σ = 2321570160. Its totient is φ = 182640000.

The previous prime is 688091399. The next prime is 688091401. The reversal of 688091400 is 4190886.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (688091399) and next prime (688091401).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (688091401) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 451039 + ... + 452561.

It is an arithmetic number, because the mean of its divisors is an integer number (16122015).

Almost surely, 2^688091400 is an apocalyptic number.

688091400 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 688091400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1160785080).

688091400 is an abundant number, since it is smaller than the sum of its proper divisors (1633478760).

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

688091400 is a wasteful number, since it uses less digits than its factorization.

688091400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1796 (or 1784 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 688091400 is about 26231.4963355124. The cubic root of 688091400 is about 882.8400837858.

The spelling of 688091400 in words is "six hundred eighty-eight million, ninety-one thousand, four hundred".