687874991 has 2 divisors, whose sum is σ = 687874992. Its totient is φ = 687874990.

The previous prime is 687874937. The next prime is 687875011. The reversal of 687874991 is 199478786.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 687874991 - 2²⁶ = 620766127 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 687874991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687874091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343937495 + 343937496.

It is an arithmetic number, because the mean of its divisors is an integer number (343937496).

Almost surely, 2^687874991 is an apocalyptic number.

687874991 is a deficient number, since it is larger than the sum of its proper divisors (1).

687874991 is an equidigital number, since it uses as much as digits as its factorization.

687874991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6096384, while the sum is 59.

The square root of 687874991 is about 26227.3710272303. The cubic root of 687874991 is about 882.7475211929.

The spelling of 687874991 in words is "six hundred eighty-seven million, eight hundred seventy-four thousand, nine hundred ninety-one".