688924042 has 4 divisors (see below), whose sum is σ = 1033386066. Its totient is φ = 344462020.

The previous prime is 688924039. The next prime is 688924069. The reversal of 688924042 is 240429886.

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

It can be written as a sum of positive squares in only one way, i.e., 519429681 + 169494361 = 22791^2 + 13019^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 688924042.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172231009 + ... + 172231012.

Almost surely, 2^688924042 is an apocalyptic number.

688924042 is a deficient number, since it is larger than the sum of its proper divisors (344462024).

688924042 is a wasteful number, since it uses less digits than its factorization.

688924042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344462023.

The product of its (nonzero) digits is 221184, while the sum is 43.

The square root of 688924042 is about 26247.3625722662. The cubic root of 688924042 is about 883.1960410650.

The spelling of 688924042 in words is "six hundred eighty-eight million, nine hundred twenty-four thousand, forty-two".