1666216216 has 32 divisors (see below), whose sum is σ = 3574910880. Its totient is φ = 713203200.

The previous prime is 1666216207. The next prime is 1666216243. The reversal of 1666216216 is 6126126661.

It is a super-2 number, since 2×1666216216² = 5552552956922717312, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27856 + ... + 64096.

It is an arithmetic number, because the mean of its divisors is an integer number (111715965).

Almost surely, 2^1666216216 is an apocalyptic number.

It is an amenable number.

1666216216 is an abundant number, since it is smaller than the sum of its proper divisors (1908694664).

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

1666216216 is a wasteful number, since it uses less digits than its factorization.

1666216216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37075 (or 37071 counting only the distinct ones).

The product of its digits is 31104, while the sum is 37.

The square root of 1666216216 is about 40819.3118021360. The cubic root of 1666216216 is about 1185.5242782084.

The spelling of 1666216216 in words is "one billion, six hundred sixty-six million, two hundred sixteen thousand, two hundred sixteen".