1666220612 has 48 divisors (see below), whose sum is σ = 3496442880. Its totient is φ = 679708800.

The previous prime is 1666220603. The next prime is 1666220617. The reversal of 1666220612 is 2160226661.

It is a super-2 number, since 2×1666220612² = 5552582255707309088, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1666220617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37214 + ... + 68682.

It is an arithmetic number, because the mean of its divisors is an integer number (72842560).

Almost surely, 2^1666220612 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666220612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1748221440).

1666220612 is an abundant number, since it is smaller than the sum of its proper divisors (1830222268).

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

1666220612 is a wasteful number, since it uses less digits than its factorization.

1666220612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31572 (or 31570 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 1666220612 is about 40819.3656491622. The cubic root of 1666220612 is about 1185.5253208022.

The spelling of 1666220612 in words is "one billion, six hundred sixty-six million, two hundred twenty thousand, six hundred twelve".