266661220 has 48 divisors (see below), whose sum is σ = 657296640. Its totient is φ = 88953984.

The previous prime is 266661217. The next prime is 266661259. The reversal of 266661220 is 22166662.

266661220 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-4 number, since 4×266661220⁴ (a number of 35 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 20560 + ... + 30919.

It is an arithmetic number, because the mean of its divisors is an integer number (13693680).

Almost surely, 2^266661220 is an apocalyptic number.

266661220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

266661220 is an abundant number, since it is smaller than the sum of its proper divisors (390635420).

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

266661220 is a wasteful number, since it uses less digits than its factorization.

266661220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51532 (or 51530 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 266661220 is about 16329.7648482763. The cubic root of 266661220 is about 643.6552074582.

The spelling of 266661220 in words is "two hundred sixty-six million, six hundred sixty-one thousand, two hundred twenty".