688491620 has 24 divisors (see below), whose sum is σ = 1446984000. Its totient is φ = 275177312.

The previous prime is 688491611. The next prime is 688491623. The reversal of 688491620 is 26194886.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (688491623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13331 + ... + 39429.

It is an arithmetic number, because the mean of its divisors is an integer number (60291000).

Almost surely, 2^688491620 is an apocalyptic number.

It is an amenable number.

688491620 is an abundant number, since it is smaller than the sum of its proper divisors (758492380).

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

688491620 is a wasteful number, since it uses less digits than its factorization.

688491620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27427 (or 27425 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 688491620 is about 26239.1238420798. The cubic root of 688491620 is about 883.0112150130.

The spelling of 688491620 in words is "six hundred eighty-eight million, four hundred ninety-one thousand, six hundred twenty".