18213116409 has 20 divisors (see below), whose sum is σ = 27211169700. Its totient is φ = 12140327520.

The previous prime is 18213116401. The next prime is 18213116429. The reversal of 18213116409 is 90461131281.

18213116409 is a `hidden beast` number, since 1 + 8 + 2 + 1 + 3 + 1 + 1 + 640 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6387206400 + 11825910009 = 79920^2 + 108747^2 .

It is not a de Polignac number, because 18213116409 - 2³ = 18213116401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18213116401) 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 19 ways as a sum of consecutive naturals, for example, 803767 + ... + 826115.

It is an arithmetic number, because the mean of its divisors is an integer number (1360558485).

Almost surely, 2^18213116409 is an apocalyptic number.

It is an amenable number.

18213116409 is a deficient number, since it is larger than the sum of its proper divisors (8998053291).

18213116409 is a wasteful number, since it uses less digits than its factorization.

18213116409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32422 (or 32413 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The spelling of 18213116409 in words is "eighteen billion, two hundred thirteen million, one hundred sixteen thousand, four hundred nine".