688401868 has 48 divisors (see below), whose sum is σ = 1567286784. Its totient is φ = 256544640.

The previous prime is 688401851. The next prime is 688401869. The reversal of 688401868 is 868104886.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (688401869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41505 + ... + 55672.

It is an arithmetic number, because the mean of its divisors is an integer number (32651808).

Almost surely, 2^688401868 is an apocalyptic number.

It is an amenable number.

688401868 is an abundant number, since it is smaller than the sum of its proper divisors (878884916).

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

688401868 is a wasteful number, since it uses less digits than its factorization.

688401868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97222 (or 97220 counting only the distinct ones).

The product of its (nonzero) digits is 589824, while the sum is 49.

The square root of 688401868 is about 26237.4135158174. The cubic root of 688401868 is about 882.9728434656.

The spelling of 688401868 in words is "six hundred eighty-eight million, four hundred one thousand, eight hundred sixty-eight".