2111920709 has 4 divisors (see below), whose sum is σ = 2112019980. Its totient is φ = 2111821440.

The previous prime is 2111920691. The next prime is 2111920721. The reversal of 2111920709 is 9070291112.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1909427809 + 202492900 = 43697^2 + 14230^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111920709 - 2²⁴ = 2095143493 is a prime.

It is a super-2 number, since 2×2111920709² = 8920418162206125362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111920609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3314 + ... + 65075.

It is an arithmetic number, because the mean of its divisors is an integer number (528004995).

Almost surely, 2^2111920709 is an apocalyptic number.

It is an amenable number.

2111920709 is a deficient number, since it is larger than the sum of its proper divisors (99271).

2111920709 is an equidigital number, since it uses as much as digits as its factorization.

2111920709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99270.

The product of its (nonzero) digits is 2268, while the sum is 32.

The square root of 2111920709 is about 45955.6384897436. The cubic root of 2111920709 is about 1282.9976756986.

The spelling of 2111920709 in words is "two billion, one hundred eleven million, nine hundred twenty thousand, seven hundred nine".