18159920427 has 30 divisors (see below), whose sum is σ = 26675871060. Its totient is φ = 10988895720.

The previous prime is 18159920419. The next prime is 18159920521. The reversal of 18159920427 is 72402995181.

It is a happy number.

It is not a de Polignac number, because 18159920427 - 2³ = 18159920419 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18159927427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 28242168 + ... + 28242810.

It is an arithmetic number, because the mean of its divisors is an integer number (889195702).

Almost surely, 2^18159920427 is an apocalyptic number.

18159920427 is a deficient number, since it is larger than the sum of its proper divisors (8515950633).

18159920427 is an frugal number, since it uses more digits than its factorization.

18159920427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1333 (or 657 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 48.

Multiplying 18159920427 by its sum of digits (48), we get a square (871676180496 = 933636²).

The spelling of 18159920427 in words is "eighteen billion, one hundred fifty-nine million, nine hundred twenty thousand, four hundred twenty-seven".