687148018 has 4 divisors (see below), whose sum is σ = 1030722030. Its totient is φ = 343574008.

The previous prime is 687148009. The next prime is 687148019. The reversal of 687148018 is 810841786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 810841786 = 2 ⋅405420893.

It can be written as a sum of positive squares in only one way, i.e., 685235329 + 1912689 = 26177^2 + 1383^2 .

It is not an unprimeable number, because it can be changed into a prime (687148019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171787003 + ... + 171787006.

Almost surely, 2^687148018 is an apocalyptic number.

687148018 is a deficient number, since it is larger than the sum of its proper divisors (343574012).

687148018 is a wasteful number, since it uses less digits than its factorization.

687148018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343574011.

The product of its (nonzero) digits is 86016, while the sum is 43.

The square root of 687148018 is about 26213.5083115557. The cubic root of 687148018 is about 882.4364376266.

The spelling of 687148018 in words is "six hundred eighty-seven million, one hundred forty-eight thousand, eighteen".