18849179521 has 4 divisors (see below), whose sum is σ = 19168657200. Its totient is φ = 18529701844.

The previous prime is 18849179467. The next prime is 18849179533. The reversal of 18849179521 is 12597194881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12597194881 = 47 ⋅268025423.

It is a cyclic number.

It is not a de Polignac number, because 18849179521 - 2¹³ = 18849171329 is a prime.

It is a super-2 number, since 2×18849179521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18849179551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159738751 + ... + 159738868.

It is an arithmetic number, because the mean of its divisors is an integer number (4792164300).

Almost surely, 2^18849179521 is an apocalyptic number.

It is an amenable number.

18849179521 is a deficient number, since it is larger than the sum of its proper divisors (319477679).

18849179521 is an equidigital number, since it uses as much as digits as its factorization.

18849179521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319477678.

The product of its digits is 1451520, while the sum is 55.

The spelling of 18849179521 in words is "eighteen billion, eight hundred forty-nine million, one hundred seventy-nine thousand, five hundred twenty-one".