688564242 has 24 divisors (see below), whose sum is σ = 1494667980. Its totient is φ = 229093920.

The previous prime is 688564231. The next prime is 688564267. The reversal of 688564242 is 242465886.

688564242 is a `hidden beast` number, since 6 + 88 + 564 + 2 + 4 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 643687641 + 44876601 = 25371^2 + 6699^2 .

It is a super-2 number, since 2×688564242² = 948241430722069128, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25617 + ... + 45092.

Almost surely, 2^688564242 is an apocalyptic number.

688564242 is an abundant number, since it is smaller than the sum of its proper divisors (806103738).

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

688564242 is a wasteful number, since it uses less digits than its factorization.

688564242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71258 (or 71255 counting only the distinct ones).

The product of its digits is 737280, while the sum is 45.

The square root of 688564242 is about 26240.5076551503. The cubic root of 688564242 is about 883.0422605547.

The spelling of 688564242 in words is "six hundred eighty-eight million, five hundred sixty-four thousand, two hundred forty-two".