18439948571 has 32 divisors (see below), whose sum is σ = 21538483200. Its totient is φ = 15609797280.

The previous prime is 18439948561. The next prime is 18439948577. The reversal of 18439948571 is 17584993481.

It is not a de Polignac number, because 18439948571 - 2¹⁸ = 18439686427 is a prime.

It is a super-2 number, since 2×18439948571² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18439948571.

It is not an unprimeable number, because it can be changed into a prime (18439948577) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7882520 + ... + 7884858.

It is an arithmetic number, because the mean of its divisors is an integer number (673077600).

Almost surely, 2^18439948571 is an apocalyptic number.

18439948571 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18439948571 is a deficient number, since it is larger than the sum of its proper divisors (3098534629).

18439948571 is a wasteful number, since it uses less digits than its factorization.

18439948571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2999.

The product of its digits is 8709120, while the sum is 59.

The spelling of 18439948571 in words is "eighteen billion, four hundred thirty-nine million, nine hundred forty-eight thousand, five hundred seventy-one".