687975919 has 4 divisors (see below), whose sum is σ = 688043896. Its totient is φ = 687907944.

The previous prime is 687975917. The next prime is 687975923. The reversal of 687975919 is 919579786.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 687975919 - 2¹ = 687975917 is a prime.

It is a super-2 number, since 2×687975919² = 946621730247789122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687975917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15429 + ... + 40174.

It is an arithmetic number, because the mean of its divisors is an integer number (172010974).

Almost surely, 2^687975919 is an apocalyptic number.

687975919 is a deficient number, since it is larger than the sum of its proper divisors (67977).

687975919 is a wasteful number, since it uses less digits than its factorization.

687975919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67976.

The product of its digits is 8573040, while the sum is 61.

The square root of 687975919 is about 26229.2950534321. The cubic root of 687975919 is about 882.7906925956.

The spelling of 687975919 in words is "six hundred eighty-seven million, nine hundred seventy-five thousand, nine hundred nineteen".