18205973 has 2 divisors, whose sum is σ = 18205974. Its totient is φ = 18205972.

The previous prime is 18205951. The next prime is 18205991. The reversal of 18205973 is 37950281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17825284 + 380689 = 4222^2 + 617^2 .

It is a cyclic number.

It is not a de Polignac number, because 18205973 - 2⁶ = 18205909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18205273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9102986 + 9102987.

It is an arithmetic number, because the mean of its divisors is an integer number (9102987).

Almost surely, 2^18205973 is an apocalyptic number.

It is an amenable number.

18205973 is a deficient number, since it is larger than the sum of its proper divisors (1).

18205973 is an equidigital number, since it uses as much as digits as its factorization.

18205973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 18205973 is about 4266.8457905108. The cubic root of 18205973 is about 263.0699838335.

The spelling of 18205973 in words is "eighteen million, two hundred five thousand, nine hundred seventy-three".