511687997 has 4 divisors (see below), whose sum is σ = 514285596. Its totient is φ = 509090400.

The previous prime is 511687933. The next prime is 511688027. The reversal of 511687997 is 799786115.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 799786115 = 5 ⋅159957223.

It can be written as a sum of positive squares in 2 ways, for example, as 226382116 + 285305881 = 15046^2 + 16891^2 .

It is a cyclic number.

It is not a de Polignac number, because 511687997 - 2⁶ = 511687933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (511687597) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1298504 + ... + 1298897.

It is an arithmetic number, because the mean of its divisors is an integer number (128571399).

Almost surely, 2^511687997 is an apocalyptic number.

It is an amenable number.

511687997 is a deficient number, since it is larger than the sum of its proper divisors (2597599).

511687997 is a wasteful number, since it uses less digits than its factorization.

511687997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2597598.

The product of its digits is 952560, while the sum is 53.

The square root of 511687997 is about 22620.5215899192. The cubic root of 511687997 is about 799.8374654179.

The spelling of 511687997 in words is "five hundred eleven million, six hundred eighty-seven thousand, nine hundred ninety-seven".