687820087 has 4 divisors (see below), whose sum is σ = 696107160. Its totient is φ = 679533016.

The previous prime is 687820031. The next prime is 687820093. The reversal of 687820087 is 780028786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 780028786 = 2 ⋅390014393.

It is a cyclic number.

It is not a de Polignac number, because 687820087 - 2¹⁵ = 687787319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687820027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4143412 + ... + 4143577.

It is an arithmetic number, because the mean of its divisors is an integer number (174026790).

Almost surely, 2^687820087 is an apocalyptic number.

687820087 is a deficient number, since it is larger than the sum of its proper divisors (8287073).

687820087 is an equidigital number, since it uses as much as digits as its factorization.

687820087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8287072.

The product of its (nonzero) digits is 301056, while the sum is 46.

The square root of 687820087 is about 26226.3243135595. The cubic root of 687820087 is about 882.7240345323.

The spelling of 687820087 in words is "six hundred eighty-seven million, eight hundred twenty thousand, eighty-seven".