18420172917 has 32 divisors (see below), whose sum is σ = 24984115200. Its totient is φ = 12070618560.

The previous prime is 18420172873. The next prime is 18420172957. The reversal of 18420172917 is 71927102481.

It is not a de Polignac number, because 18420172917 - 2⁷ = 18420172789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18420172957) 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 31 ways as a sum of consecutive naturals, for example, 24791248 + ... + 24791990.

It is an arithmetic number, because the mean of its divisors is an integer number (780753600).

Almost surely, 2^18420172917 is an apocalyptic number.

It is an amenable number.

18420172917 is a deficient number, since it is larger than the sum of its proper divisors (6563942283).

18420172917 is a wasteful number, since it uses less digits than its factorization.

18420172917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1393.

The product of its (nonzero) digits is 56448, while the sum is 42.

The spelling of 18420172917 in words is "eighteen billion, four hundred twenty million, one hundred seventy-two thousand, nine hundred seventeen".