18817117801 has 16 divisors (see below), whose sum is σ = 19441282960. Its totient is φ = 18204549120.

The previous prime is 18817117793. The next prime is 18817117841. The reversal of 18817117801 is 10871171881.

It can be written as a sum of positive squares in 8 ways, for example, as 1878355600 + 16938762201 = 43340^2 + 130149^2 .

It is a 5-Lehmer number, since φ(18817117801) divides (18817117801-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 18817117801 - 2³ = 18817117793 is a prime.

It is a super-2 number, since 2×18817117801² (a number of 21 digits) contains 22 as substring.

It is the 137176-th Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18817117841) by changing a digit.

It is a nontrivial repunit in base 137175.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1655305 + ... + 1666633.

It is an arithmetic number, because the mean of its divisors is an integer number (1215080185).

Almost surely, 2^18817117801 is an apocalyptic number.

It is an amenable number.

18817117801 is a deficient number, since it is larger than the sum of its proper divisors (624165159).

18817117801 is a wasteful number, since it uses less digits than its factorization.

18817117801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11836.

The product of its (nonzero) digits is 25088, while the sum is 43.

The spelling of 18817117801 in words is "eighteen billion, eight hundred seventeen million, one hundred seventeen thousand, eight hundred one".