520991217 has 8 divisors (see below), whose sum is σ = 771838880. Its totient is φ = 347327460.

The previous prime is 520991203. The next prime is 520991227. The reversal of 520991217 is 712199025.

520991217 is a `hidden beast` number, since 520 + 9 + 9 + 121 + 7 = 666.

It is not a de Polignac number, because 520991217 - 2⁷ = 520991089 is a prime.

It is a super-2 number, since 2×520991217² = 542863696382282178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (520991227) 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 in 7 ways as a sum of consecutive naturals, for example, 9647959 + ... + 9648012.

It is an arithmetic number, because the mean of its divisors is an integer number (96479860).

Almost surely, 2^520991217 is an apocalyptic number.

It is an amenable number.

520991217 is a deficient number, since it is larger than the sum of its proper divisors (250847663).

520991217 is a wasteful number, since it uses less digits than its factorization.

520991217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19295980 (or 19295974 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 36.

The square root of 520991217 is about 22825.2320251077. The cubic root of 520991217 is about 804.6557776268.

The spelling of 520991217 in words is "five hundred twenty million, nine hundred ninety-one thousand, two hundred seventeen".