520551666 has 24 divisors (see below), whose sum is σ = 1128308220. Its totient is φ = 173448576.

The previous prime is 520551601. The next prime is 520551673. The reversal of 520551666 is 666155025.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 489515625 + 31036041 = 22125^2 + 5571^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 520551666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64006 + ... + 71678.

Almost surely, 2^520551666 is an apocalyptic number.

520551666 is an abundant number, since it is smaller than the sum of its proper divisors (607756554).

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

520551666 is a wasteful number, since it uses less digits than its factorization.

520551666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11450 (or 11447 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 520551666 is about 22815.6013727449. The cubic root of 520551666 is about 804.4294227137.

The spelling of 520551666 in words is "five hundred twenty million, five hundred fifty-one thousand, six hundred sixty-six".