520778813 has 8 divisors (see below), whose sum is σ = 524084736. Its totient is φ = 517482000.

The previous prime is 520778801. The next prime is 520778831. The reversal of 520778813 is 318877025.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 520778813 - 2¹⁸ = 520516669 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 (520778893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138863 + ... + 142563.

It is an arithmetic number, because the mean of its divisors is an integer number (65510592).

Almost surely, 2^520778813 is an apocalyptic number.

It is an amenable number.

520778813 is a deficient number, since it is larger than the sum of its proper divisors (3305923).

520778813 is a wasteful number, since it uses less digits than its factorization.

520778813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4555.

The product of its (nonzero) digits is 94080, while the sum is 41.

The square root of 520778813 is about 22820.5787174646. The cubic root of 520778813 is about 804.5464121634.

The spelling of 520778813 in words is "five hundred twenty million, seven hundred seventy-eight thousand, eight hundred thirteen".