18705121545 has 32 divisors (see below), whose sum is σ = 33015807360. Its totient is φ = 8967242240.

The previous prime is 18705121543. The next prime is 18705121549. The reversal of 18705121545 is 54512150781.

It is not a de Polignac number, because 18705121545 - 2¹ = 18705121543 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18705121543) 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, 622194 + ... + 651563.

It is an arithmetic number, because the mean of its divisors is an integer number (1031743980).

Almost surely, 2^18705121545 is an apocalyptic number.

18705121545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18705121545 is a deficient number, since it is larger than the sum of its proper divisors (14310685815).

18705121545 is a wasteful number, since it uses less digits than its factorization.

18705121545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273865.

The product of its (nonzero) digits is 56000, while the sum is 39.

The spelling of 18705121545 in words is "eighteen billion, seven hundred five million, one hundred twenty-one thousand, five hundred forty-five".