687648914 has 4 divisors (see below), whose sum is σ = 1031473374. Its totient is φ = 343824456.

The previous prime is 687648901. The next prime is 687648961. The reversal of 687648914 is 419846786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 419846786 = 2 ⋅209923393.

It can be written as a sum of positive squares in only one way, i.e., 409860025 + 277788889 = 20245^2 + 16667^2 .

It is a super-2 number, since 2×687648914² = 945722057850758792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171912227 + ... + 171912230.

Almost surely, 2^687648914 is an apocalyptic number.

687648914 is a deficient number, since it is larger than the sum of its proper divisors (343824460).

687648914 is a wasteful number, since it uses less digits than its factorization.

687648914 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343824459.

The product of its digits is 2322432, while the sum is 53.

The square root of 687648914 is about 26223.0607290606. The cubic root of 687648914 is about 882.6508026605.

The spelling of 687648914 in words is "six hundred eighty-seven million, six hundred forty-eight thousand, nine hundred fourteen".