511516921 has 2 divisors, whose sum is σ = 511516922. Its totient is φ = 511516920.

The previous prime is 511516919. The next prime is 511516931. The reversal of 511516921 is 129615115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 426876921 + 84640000 = 20661^2 + 9200^2 .

It is a cyclic number.

It is not a de Polignac number, because 511516921 - 2¹ = 511516919 is a prime.

Together with 511516919, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (511516931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 255758460 + 255758461.

It is an arithmetic number, because the mean of its divisors is an integer number (255758461).

Almost surely, 2^511516921 is an apocalyptic number.

It is an amenable number.

511516921 is a deficient number, since it is larger than the sum of its proper divisors (1).

511516921 is an equidigital number, since it uses as much as digits as its factorization.

511516921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 31.

The square root of 511516921 is about 22616.7398402157. The cubic root of 511516921 is about 799.7483171822.

The spelling of 511516921 in words is "five hundred eleven million, five hundred sixteen thousand, nine hundred twenty-one".