520221666 has 16 divisors (see below), whose sum is σ = 1040671584. Its totient is φ = 173369184.

The previous prime is 520221661. The next prime is 520221671. The reversal of 520221666 is 666122025.

It is an interprime number because it is at equal distance from previous prime (520221661) and next prime (520221671).

It is not an unprimeable number, because it can be changed into a prime (520221661) 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, 39741 + ... + 51183.

It is an arithmetic number, because the mean of its divisors is an integer number (65041974).

Almost surely, 2^520221666 is an apocalyptic number.

520221666 is an abundant number, since it is smaller than the sum of its proper divisors (520449918).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

520221666 is a wasteful number, since it uses less digits than its factorization.

520221666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19025.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 520221666 is about 22808.3683326975. The cubic root of 520221666 is about 804.2593993568.

The spelling of 520221666 in words is "five hundred twenty million, two hundred twenty-one thousand, six hundred sixty-six".