2166921903291 has 4 divisors (see below), whose sum is σ = 2889229204392. Its totient is φ = 1444614602192.

The previous prime is 2166921903283. The next prime is 2166921903319. The reversal of 2166921903291 is 1923091296612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2166921903291 - 2³ = 2166921903283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2166921903221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 361153650546 + ... + 361153650551.

It is an arithmetic number, because the mean of its divisors is an integer number (722307301098).

Almost surely, 2^{2166921903291} is an apocalyptic number.

2166921903291 is a deficient number, since it is larger than the sum of its proper divisors (722307301101).

2166921903291 is an equidigital number, since it uses as much as digits as its factorization.

2166921903291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722307301100.

The product of its (nonzero) digits is 629856, while the sum is 51.

The spelling of 2166921903291 in words is "two trillion, one hundred sixty-six billion, nine hundred twenty-one million, nine hundred three thousand, two hundred ninety-one".