687131723 has 2 divisors, whose sum is σ = 687131724. Its totient is φ = 687131722.

The previous prime is 687131707. The next prime is 687131761. The reversal of 687131723 is 327131786.

687131723 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (687131761) can be obtained adding 687131723 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 687131723 - 2⁴ = 687131707 is a prime.

It is not a weakly prime, because it can be changed into another prime (687133723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343565861 + 343565862.

It is an arithmetic number, because the mean of its divisors is an integer number (343565862).

Almost surely, 2^687131723 is an apocalyptic number.

687131723 is a deficient number, since it is larger than the sum of its proper divisors (1).

687131723 is an equidigital number, since it uses as much as digits as its factorization.

687131723 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 38.

The square root of 687131723 is about 26213.1974966809. The cubic root of 687131723 is about 882.4294622176.

The spelling of 687131723 in words is "six hundred eighty-seven million, one hundred thirty-one thousand, seven hundred twenty-three".