688618145 has 4 divisors (see below), whose sum is σ = 826341780. Its totient is φ = 550894512.

The previous prime is 688618069. The next prime is 688618157. The reversal of 688618145 is 541816886.

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

It can be written as a sum of positive squares in 2 ways, for example, as 526794304 + 161823841 = 22952^2 + 12721^2 .

It is a cyclic number.

It is not a de Polignac number, because 688618145 - 2⁸ = 688617889 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 688618145.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68861810 + ... + 68861819.

It is an arithmetic number, because the mean of its divisors is an integer number (206585445).

Almost surely, 2^688618145 is an apocalyptic number.

It is an amenable number.

688618145 is a deficient number, since it is larger than the sum of its proper divisors (137723635).

688618145 is a wasteful number, since it uses less digits than its factorization.

688618145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137723634.

The product of its digits is 368640, while the sum is 47.

The square root of 688618145 is about 26241.5347302706. The cubic root of 688618145 is about 883.0653024062.

The spelling of 688618145 in words is "six hundred eighty-eight million, six hundred eighteen thousand, one hundred forty-five".