20813587186801 has 4 divisors (see below), whose sum is σ = 20921429607652. Its totient is φ = 20705744765952.

The previous prime is 20813587186789. The next prime is 20813587186831. The reversal of 20813587186801 is 10868178531802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8861189400625 + 11952397786176 = 2976775^2 + 3457224^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20813587186801 is a prime.

It is a super-2 number, since 2×20813587186801² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20813587186831) 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, 53921210136 + ... + 53921210521.

It is an arithmetic number, because the mean of its divisors is an integer number (5230357401913).

Almost surely, 2^{20813587186801} is an apocalyptic number.

It is an amenable number.

20813587186801 is a deficient number, since it is larger than the sum of its proper divisors (107842420851).

20813587186801 is a wasteful number, since it uses less digits than its factorization.

20813587186801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107842420850.

The product of its (nonzero) digits is 5160960, while the sum is 58.

The spelling of 20813587186801 in words is "twenty trillion, eight hundred thirteen billion, five hundred eighty-seven million, one hundred eighty-six thousand, eight hundred one".