511691 has 2 divisors, whose sum is σ = 511692. Its totient is φ = 511690.

The previous prime is 511669. The next prime is 511703. The reversal of 511691 is 196115.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 511691 - 2⁶ = 511627 is a prime.

It is not a weakly prime, because it can be changed into another prime (511631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 255845 + 255846.

It is an arithmetic number, because the mean of its divisors is an integer number (255846).

2⁵¹¹⁶⁹¹ is an apocalyptic number.

511691 is a deficient number, since it is larger than the sum of its proper divisors (1).

511691 is an equidigital number, since it uses as much as digits as its factorization.

511691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 270, while the sum is 23.

The square root of 511691 is about 715.3257998982. The cubic root of 511691 is about 79.9839030113.

The spelling of 511691 in words is "five hundred eleven thousand, six hundred ninety-one".