687240418 has 4 divisors (see below), whose sum is σ = 1030860630. Its totient is φ = 343620208.

The previous prime is 687240413. The next prime is 687240427. The reversal of 687240418 is 814042786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 814042786 = 2 ⋅407021393.

It can be written as a sum of positive squares in only one way, i.e., 353703249 + 333537169 = 18807^2 + 18263^2 .

It is not an unprimeable number, because it can be changed into a prime (687240413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171810103 + ... + 171810106.

Almost surely, 2^687240418 is an apocalyptic number.

687240418 is a deficient number, since it is larger than the sum of its proper divisors (343620212).

687240418 is a wasteful number, since it uses less digits than its factorization.

687240418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343620211.

The product of its (nonzero) digits is 86016, while the sum is 40.

The square root of 687240418 is about 26215.2707023979. The cubic root of 687240418 is about 882.4759892565.

The spelling of 687240418 in words is "six hundred eighty-seven million, two hundred forty thousand, four hundred eighteen".