690871 has 2 divisors, whose sum is σ = 690872. Its totient is φ = 690870.

The previous prime is 690869. The next prime is 690887. The reversal of 690871 is 178096.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 690871 - 2¹ = 690869 is a prime.

Together with 690869, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (690841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345435 + 345436.

It is an arithmetic number, because the mean of its divisors is an integer number (345436).

2⁶⁹⁰⁸⁷¹ is an apocalyptic number.

690871 is a deficient number, since it is larger than the sum of its proper divisors (1).

690871 is an equidigital number, since it uses as much as digits as its factorization.

690871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 690871 is about 831.1865013341. The cubic root of 690871 is about 88.4027254266.

The spelling of 690871 in words is "six hundred ninety thousand, eight hundred seventy-one".