511167661 has 2 divisors, whose sum is σ = 511167662. Its totient is φ = 511167660.

The previous prime is 511167619. The next prime is 511167667. The reversal of 511167661 is 166761115.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 424566025 + 86601636 = 20605^2 + 9306^2 .

It is a cyclic number.

It is not a de Polignac number, because 511167661 - 2⁹ = 511167149 is a prime.

It is a super-2 number, since 2×511167661² = 522584755304421842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (511167667) 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, 255583830 + 255583831.

It is an arithmetic number, because the mean of its divisors is an integer number (255583831).

Almost surely, 2^511167661 is an apocalyptic number.

It is an amenable number.

511167661 is a deficient number, since it is larger than the sum of its proper divisors (1).

511167661 is an equidigital number, since it uses as much as digits as its factorization.

511167661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 34.

The square root of 511167661 is about 22609.0172497612. The cubic root of 511167661 is about 799.5662549782.

The spelling of 511167661 in words is "five hundred eleven million, one hundred sixty-seven thousand, six hundred sixty-one".