1666610220 has 96 divisors (see below), whose sum is σ = 5255018496. Its totient is φ = 390988800.

The previous prime is 1666610201. The next prime is 1666610261. The reversal of 1666610220 is 220166661.

It is a super-3 number, since 3×1666610220³ (a number of 29 digits) contains 333 as substring.

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 31 ways as a sum of consecutive naturals, for example, 20269 + ... + 61188.

It is an arithmetic number, because the mean of its divisors is an integer number (54739776).

Almost surely, 2^1666610220 is an apocalyptic number.

1666610220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666610220 is an abundant number, since it is smaller than the sum of its proper divisors (3588408276).

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

1666610220 is a wasteful number, since it uses less digits than its factorization.

1666610220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81511 (or 81509 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 1666610220 is about 40824.1377128777. The cubic root of 1666610220 is about 1185.6177163609.

Adding to 1666610220 its reverse (220166661), we get a palindrome (1886776881).

The spelling of 1666610220 in words is "one billion, six hundred sixty-six million, six hundred ten thousand, two hundred twenty".