18205800001 has 12 divisors (see below), whose sum is σ = 18845205636. Its totient is φ = 17587445760.

The previous prime is 18205799993. The next prime is 18205800017. The reversal of 18205800001 is 10000850281.

It can be written as a sum of positive squares in 2 ways, for example, as 15926692401 + 2279107600 = 126201^2 + 47740^2 .

It is not a de Polignac number, because 18205800001 - 2³ = 18205799993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18205800601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 538081 + ... + 570913.

It is an arithmetic number, because the mean of its divisors is an integer number (1570433803).

Almost surely, 2^18205800001 is an apocalyptic number.

It is an amenable number.

18205800001 is a deficient number, since it is larger than the sum of its proper divisors (639405635).

18205800001 is an equidigital number, since it uses as much as digits as its factorization.

18205800001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33472 (or 33441 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 25.

The spelling of 18205800001 in words is "eighteen billion, two hundred five million, eight hundred thousand, one".