18885986331601 has 3 divisors (see below), whose sum is σ = 18885990677403. Its totient is φ = 18885981985800.

The previous prime is 18885986331581. The next prime is 18885986331677. The reversal of 18885986331601 is 10613368958881.

The square root of 18885986331601 is 4345801.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 8217401293201 + 10668585038400 = 2866601^2 + 3266280^2 .

It is not a de Polignac number, because 18885986331601 - 2⁴³ = 10089893309393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18885986334601) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2172901 + ... + 6518701.

It is an arithmetic number, because the mean of its divisors is an integer number (6295330225801).

Almost surely, 2^{18885986331601} is an apocalyptic number.

18885986331601 is the 4345801-st square number.

18885986331601 is the 2172901-st centered octagonal number.

It is an amenable number.

18885986331601 is a deficient number, since it is larger than the sum of its proper divisors (4345802).

18885986331601 is an frugal number, since it uses more digits than its factorization.

18885986331601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8691602 (or 4345801 counting only the distinct ones).

The product of its (nonzero) digits is 59719680, while the sum is 67.

The spelling of 18885986331601 in words is "eighteen trillion, eight hundred eighty-five billion, nine hundred eighty-six million, three hundred thirty-one thousand, six hundred one".