691877 has 2 divisors, whose sum is σ = 691878. Its totient is φ = 691876.

The previous prime is 691871. The next prime is 691891. The reversal of 691877 is 778196.

It is a happy number.

691877 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 474721 + 217156 = 689^2 + 466^2 .

It is a cyclic number.

It is not a de Polignac number, because 691877 - 2⁶ = 691813 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 691877.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345938 + 345939.

It is an arithmetic number, because the mean of its divisors is an integer number (345939).

2⁶⁹¹⁸⁷⁷ is an apocalyptic number.

It is an amenable number.

691877 is a deficient number, since it is larger than the sum of its proper divisors (1).

691877 is an equidigital number, since it uses as much as digits as its factorization.

691877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 38.

The square root of 691877 is about 831.7914402060. The cubic root of 691877 is about 88.4456133225.

The spelling of 691877 in words is "six hundred ninety-one thousand, eight hundred seventy-seven".