510911981 has 2 divisors, whose sum is σ = 510911982. Its totient is φ = 510911980.

The previous prime is 510911971. The next prime is 510911987. The reversal of 510911981 is 189119015.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 414773956 + 96138025 = 20366^2 + 9805^2 .

It is a cyclic number.

It is not a de Polignac number, because 510911981 - 2¹⁰ = 510910957 is a prime.

It is a super-2 number, since 2×510911981² = 522062104658688722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (510911987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 255455990 + 255455991.

It is an arithmetic number, because the mean of its divisors is an integer number (255455991).

Almost surely, 2^510911981 is an apocalyptic number.

It is an amenable number.

510911981 is a deficient number, since it is larger than the sum of its proper divisors (1).

510911981 is an equidigital number, since it uses as much as digits as its factorization.

510911981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 35.

The square root of 510911981 is about 22603.3621614131. The cubic root of 510911981 is about 799.4329215600.

The spelling of 510911981 in words is "five hundred ten million, nine hundred eleven thousand, nine hundred eighty-one".