512021509 has 2 divisors, whose sum is σ = 512021510. Its totient is φ = 512021508.

The previous prime is 512021507. The next prime is 512021537. The reversal of 512021509 is 905120215.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 361836484 + 150185025 = 19022^2 + 12255^2 .

It is a cyclic number.

It is not a de Polignac number, because 512021509 - 2¹ = 512021507 is a prime.

Together with 512021507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (512021507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 256010754 + 256010755.

It is an arithmetic number, because the mean of its divisors is an integer number (256010755).

Almost surely, 2^512021509 is an apocalyptic number.

It is an amenable number.

512021509 is a deficient number, since it is larger than the sum of its proper divisors (1).

512021509 is an equidigital number, since it uses as much as digits as its factorization.

512021509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 512021509 is about 22627.8922792204. The cubic root of 512021509 is about 800.0112024473.

The spelling of 512021509 in words is "five hundred twelve million, twenty-one thousand, five hundred nine".