688742 has 4 divisors (see below), whose sum is σ = 1033116. Its totient is φ = 344370.

The previous prime is 688741. The next prime is 688747. The reversal of 688742 is 247886.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172184 + ... + 172187.

It is an arithmetic number, because the mean of its divisors is an integer number (258279).

2⁶⁸⁸⁷⁴² is an apocalyptic number.

688742 is a deficient number, since it is larger than the sum of its proper divisors (344374).

688742 is a wasteful number, since it uses less digits than its factorization.

688742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344373.

The product of its digits is 21504, while the sum is 35.

The square root of 688742 is about 829.9048138190. The cubic root of 688742 is about 88.3118242001.

The spelling of 688742 in words is "six hundred eighty-eight thousand, seven hundred forty-two".