520963991 has 4 divisors (see below), whose sum is σ = 528301584. Its totient is φ = 513626400.

The previous prime is 520963981. The next prime is 520964029. The reversal of 520963991 is 199369025.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 520963991 - 2¹⁴ = 520947607 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 (520963931) 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 3 ways as a sum of consecutive naturals, for example, 3668690 + ... + 3668831.

It is an arithmetic number, because the mean of its divisors is an integer number (132075396).

Almost surely, 2^520963991 is an apocalyptic number.

520963991 is a deficient number, since it is larger than the sum of its proper divisors (7337593).

520963991 is an equidigital number, since it uses as much as digits as its factorization.

520963991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7337592.

The product of its (nonzero) digits is 131220, while the sum is 44.

The square root of 520963991 is about 22824.6356159304. The cubic root of 520963991 is about 804.6417607943.

The spelling of 520963991 in words is "five hundred twenty million, nine hundred sixty-three thousand, nine hundred ninety-one".