520670721 has 8 divisors (see below), whose sum is σ = 694473184. Its totient is φ = 346991040.

The previous prime is 520670681. The next prime is 520670723. The reversal of 520670721 is 127076025.

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

It is not a de Polignac number, because 520670721 - 2⁹ = 520670209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (520670723) 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, 20296 + ... + 38121.

It is an arithmetic number, because the mean of its divisors is an integer number (86809148).

Almost surely, 2^520670721 is an apocalyptic number.

It is an amenable number.

520670721 is a deficient number, since it is larger than the sum of its proper divisors (173802463).

520670721 is a wasteful number, since it uses less digits than its factorization.

520670721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61391.

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 520670721 is about 22818.2102935353. The cubic root of 520670721 is about 804.4907448653.

The spelling of 520670721 in words is "five hundred twenty million, six hundred seventy thousand, seven hundred twenty-one".