18988440405 has 32 divisors (see below), whose sum is σ = 33149675520. Its totient is φ = 9204790080.

The previous prime is 18988440397. The next prime is 18988440439. The reversal of 18988440405 is 50404488981.

It is not a de Polignac number, because 18988440405 - 2³ = 18988440397 is a prime.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1581816 + ... + 1593774.

It is an arithmetic number, because the mean of its divisors is an integer number (1035927360).

Almost surely, 2^18988440405 is an apocalyptic number.

18988440405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18988440405 is a deficient number, since it is larger than the sum of its proper divisors (14161235115).

18988440405 is a wasteful number, since it uses less digits than its factorization.

18988440405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21601.

The product of its (nonzero) digits is 1474560, while the sum is 51.

The spelling of 18988440405 in words is "eighteen billion, nine hundred eighty-eight million, four hundred forty thousand, four hundred five".