18191101 has 2 divisors, whose sum is σ = 18191102. Its totient is φ = 18191100.

The previous prime is 18191081. The next prime is 18191111. The reversal of 18191101 is 10119181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15132100 + 3059001 = 3890^2 + 1749^2 .

It is an emirp because it is prime and its reverse (10119181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18191101 - 2⁷ = 18190973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18191111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9095550 + 9095551.

It is an arithmetic number, because the mean of its divisors is an integer number (9095551).

Almost surely, 2^18191101 is an apocalyptic number.

It is an amenable number.

18191101 is a deficient number, since it is larger than the sum of its proper divisors (1).

18191101 is an equidigital number, since it uses as much as digits as its factorization.

18191101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 22.

The square root of 18191101 is about 4265.1026951294. The cubic root of 18191101 is about 262.9983325758.

The spelling of 18191101 in words is "eighteen million, one hundred ninety-one thousand, one hundred one".