2118491709 has 4 divisors (see below), whose sum is σ = 2824655616. Its totient is φ = 1412327804.

The previous prime is 2118491657. The next prime is 2118491717. The reversal of 2118491709 is 9071948112.

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 2118491709 - 2¹⁶ = 2118426173 is a prime.

It is a super-2 number, since 2×2118491709² = 8976014242203481362, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2118491759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353081949 + ... + 353081954.

It is an arithmetic number, because the mean of its divisors is an integer number (706163904).

Almost surely, 2^2118491709 is an apocalyptic number.

It is an amenable number.

2118491709 is a deficient number, since it is larger than the sum of its proper divisors (706163907).

2118491709 is an equidigital number, since it uses as much as digits as its factorization.

2118491709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706163906.

The product of its (nonzero) digits is 36288, while the sum is 42.

The square root of 2118491709 is about 46027.0758249967. The cubic root of 2118491709 is about 1284.3269316030.

The spelling of 2118491709 in words is "two billion, one hundred eighteen million, four hundred ninety-one thousand, seven hundred nine".