687112121 has 2 divisors, whose sum is σ = 687112122. Its totient is φ = 687112120.

The previous prime is 687112091. The next prime is 687112133. The reversal of 687112121 is 121211786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 503374096 + 183738025 = 22436^2 + 13555^2 .

It is a cyclic number.

It is not a de Polignac number, because 687112121 - 2⁶ = 687112057 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (687142121) 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 as a sum of consecutive naturals, namely, 343556060 + 343556061.

It is an arithmetic number, because the mean of its divisors is an integer number (343556061).

Almost surely, 2^687112121 is an apocalyptic number.

It is an amenable number.

687112121 is a deficient number, since it is larger than the sum of its proper divisors (1).

687112121 is an equidigital number, since it uses as much as digits as its factorization.

687112121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1344, while the sum is 29.

The square root of 687112121 is about 26212.8235983841. The cubic root of 687112121 is about 882.4210710332.

The spelling of 687112121 in words is "six hundred eighty-seven million, one hundred twelve thousand, one hundred twenty-one".