2118697409 has 2 divisors, whose sum is σ = 2118697410. Its totient is φ = 2118697408.

The previous prime is 2118697393. The next prime is 2118697423. The reversal of 2118697409 is 9047968112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2069977009 + 48720400 = 45497^2 + 6980^2 .

It is a cyclic number.

It is not a de Polignac number, because 2118697409 - 2⁴ = 2118697393 is a prime.

It is not a weakly prime, because it can be changed into another prime (2118691409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1059348704 + 1059348705.

It is an arithmetic number, because the mean of its divisors is an integer number (1059348705).

Almost surely, 2^2118697409 is an apocalyptic number.

It is an amenable number.

2118697409 is a deficient number, since it is larger than the sum of its proper divisors (1).

2118697409 is an equidigital number, since it uses as much as digits as its factorization.

2118697409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 47.

The square root of 2118697409 is about 46029.3103250527. The cubic root of 2118697409 is about 1284.3684985189.

The spelling of 2118697409 in words is "two billion, one hundred eighteen million, six hundred ninety-seven thousand, four hundred nine".