18872173 has 2 divisors, whose sum is σ = 18872174. Its totient is φ = 18872172.

The previous prime is 18872143. The next prime is 18872201. The reversal of 18872173 is 37127881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14884164 + 3988009 = 3858^2 + 1997^2 .

It is a cyclic number.

It is not a de Polignac number, because 18872173 - 2¹⁷ = 18741101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18872123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9436086 + 9436087.

It is an arithmetic number, because the mean of its divisors is an integer number (9436087).

Almost surely, 2^18872173 is an apocalyptic number.

It is an amenable number.

18872173 is a deficient number, since it is larger than the sum of its proper divisors (1).

18872173 is an equidigital number, since it uses as much as digits as its factorization.

18872173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18816, while the sum is 37.

The square root of 18872173 is about 4344.2114359225. The cubic root of 18872173 is about 266.2404077157.

It can be divided in two parts, 188 and 72173, that added together give a square (72361 = 269²).

The spelling of 18872173 in words is "eighteen million, eight hundred seventy-two thousand, one hundred seventy-three".