18847571621641 has 9 divisors (see below), whose sum is σ = 21924761523399. Its totient is φ = 16155035341704.

The previous prime is 18847571621597. The next prime is 18847571621653. The reversal of 18847571621641 is 14612617574881.

The square root of 18847571621641 is 4341379.

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

It can be written as a sum of positive squares in only one way, i.e., 18556839295225 + 290732326416 = 4307765^2 + 539196^2 .

It is not a de Polignac number, because 18847571621641 - 2⁹ = 18847571621129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18847571621641.

It is not an unprimeable number, because it can be changed into a prime (18847571621741) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 30079555 + ... + 30699751.

It is an arithmetic number, because the mean of its divisors is an integer number (2436084613711).

Almost surely, 2^{18847571621641} is an apocalyptic number.

18847571621641 is the 4341379-th square number.

18847571621641 is the 2170690-th centered octagonal number.

It is an amenable number.

18847571621641 is a deficient number, since it is larger than the sum of its proper divisors (3077189901758).

18847571621641 is an frugal number, since it uses more digits than its factorization.

18847571621641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1240408 (or 620204 counting only the distinct ones).

The product of its digits is 18063360, while the sum is 61.

The spelling of 18847571621641 in words is "eighteen trillion, eight hundred forty-seven billion, five hundred seventy-one million, six hundred twenty-one thousand, six hundred forty-one".