18420385945 has 16 divisors (see below), whose sum is σ = 24015478032. Its totient is φ = 13482362880.

The previous prime is 18420385939. The next prime is 18420385979. The reversal of 18420385945 is 54958302481.

It can be written as a sum of positive squares in 8 ways, for example, as 6373786896 + 12046599049 = 79836^2 + 109757^2 .

It is not a de Polignac number, because 18420385945 - 2³ = 18420385937 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1246596 + ... + 1261285.

It is an arithmetic number, because the mean of its divisors is an integer number (1500967377).

Almost surely, 2^18420385945 is an apocalyptic number.

It is an amenable number.

18420385945 is a deficient number, since it is larger than the sum of its proper divisors (5595092087).

18420385945 is a wasteful number, since it uses less digits than its factorization.

18420385945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2508012.

The product of its (nonzero) digits is 1382400, while the sum is 49.

The spelling of 18420385945 in words is "eighteen billion, four hundred twenty million, three hundred eighty-five thousand, nine hundred forty-five".