687459391 has 2 divisors, whose sum is σ = 687459392. Its totient is φ = 687459390.

The previous prime is 687459373. The next prime is 687459401. The reversal of 687459391 is 193954786.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 687459391 - 2⁹ = 687458879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687459191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343729695 + 343729696.

It is an arithmetic number, because the mean of its divisors is an integer number (343729696).

Almost surely, 2^687459391 is an apocalyptic number.

687459391 is a deficient number, since it is larger than the sum of its proper divisors (1).

687459391 is an equidigital number, since it uses as much as digits as its factorization.

687459391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 52.

The square root of 687459391 is about 26219.4468095725. The cubic root of 687459391 is about 882.5697060450.

The spelling of 687459391 in words is "six hundred eighty-seven million, four hundred fifty-nine thousand, three hundred ninety-one".