2105215666 has 8 divisors (see below), whose sum is σ = 3158497260. Its totient is φ = 1052383248.

The previous prime is 2105215657. The next prime is 2105215741. The reversal of 2105215666 is 6665125012.

It can be written as a sum of positive squares in 2 ways, for example, as 1345055625 + 760160041 = 36675^2 + 27571^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100321 + ... + 119476.

Almost surely, 2^2105215666 is an apocalyptic number.

2105215666 is a deficient number, since it is larger than the sum of its proper divisors (1053281594).

2105215666 is a wasteful number, since it uses less digits than its factorization.

2105215666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224588.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 2105215666 is about 45882.6292402691. The cubic root of 2105215666 is about 1281.6384588500.

The spelling of 2105215666 in words is "two billion, one hundred five million, two hundred fifteen thousand, six hundred sixty-six".