1666322220 has 48 divisors (see below), whose sum is σ = 4670154720. Its totient is φ = 443928576.

The previous prime is 1666322219. The next prime is 1666322233. The reversal of 1666322220 is 222236661.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52876 + ... + 78284.

It is an arithmetic number, because the mean of its divisors is an integer number (97294890).

Almost surely, 2^1666322220 is an apocalyptic number.

1666322220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666322220 is an abundant number, since it is smaller than the sum of its proper divisors (3003832500).

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

1666322220 is a wasteful number, since it uses less digits than its factorization.

1666322220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26514 (or 26512 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 1666322220 is about 40820.6102355171. The cubic root of 1666322220 is about 1185.5494185332.

Adding to 1666322220 its reverse (222236661), we get a palindrome (1888558881).

It can be divided in two parts, 16663 and 22220, that added together give a palindrome (38883).

The spelling of 1666322220 in words is "one billion, six hundred sixty-six million, three hundred twenty-two thousand, two hundred twenty".