2119818661 has 4 divisors (see below), whose sum is σ = 2127879072. Its totient is φ = 2111758252.

The previous prime is 2119818647. The next prime is 2119818683. The reversal of 2119818661 is 1668189112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2119818661 - 2⁹ = 2119818149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2119818691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4029811 + ... + 4030336.

It is an arithmetic number, because the mean of its divisors is an integer number (531969768).

Almost surely, 2^2119818661 is an apocalyptic number.

It is an amenable number.

2119818661 is a deficient number, since it is larger than the sum of its proper divisors (8060411).

2119818661 is an equidigital number, since it uses as much as digits as its factorization.

2119818661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8060410.

The product of its digits is 41472, while the sum is 43.

The square root of 2119818661 is about 46041.4884750700. The cubic root of 2119818661 is about 1284.5950287089.

The spelling of 2119818661 in words is "two billion, one hundred nineteen million, eight hundred eighteen thousand, six hundred sixty-one".