687898987 has 2 divisors, whose sum is σ = 687898988. Its totient is φ = 687898986.

The previous prime is 687898979. The next prime is 687898997. The reversal of 687898987 is 789898786.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 687898987 - 2³ = 687898979 is a prime.

It is not a weakly prime, because it can be changed into another prime (687898997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343949493 + 343949494.

It is an arithmetic number, because the mean of its divisors is an integer number (343949494).

Almost surely, 2^687898987 is an apocalyptic number.

687898987 is a deficient number, since it is larger than the sum of its proper divisors (1).

687898987 is an equidigital number, since it uses as much as digits as its factorization.

687898987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97542144, while the sum is 70.

The square root of 687898987 is about 26227.8284842646. The cubic root of 687898987 is about 882.7577857339.

The spelling of 687898987 in words is "six hundred eighty-seven million, eight hundred ninety-eight thousand, nine hundred eighty-seven".