687856319 has 2 divisors, whose sum is σ = 687856320. Its totient is φ = 687856318.

The previous prime is 687856277. The next prime is 687856343. The reversal of 687856319 is 913658786.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 687856319 - 2¹⁶ = 687790783 is a prime.

It is a super-2 number, since 2×687856319² = 946292631176459522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687856019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343928159 + 343928160.

It is an arithmetic number, because the mean of its divisors is an integer number (343928160).

Almost surely, 2^687856319 is an apocalyptic number.

687856319 is a deficient number, since it is larger than the sum of its proper divisors (1).

687856319 is an equidigital number, since it uses as much as digits as its factorization.

687856319 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2177280, while the sum is 53.

The square root of 687856319 is about 26227.0150608109. The cubic root of 687856319 is about 882.7395338837.

The spelling of 687856319 in words is "six hundred eighty-seven million, eight hundred fifty-six thousand, three hundred nineteen".