18241591 has 2 divisors, whose sum is σ = 18241592. Its totient is φ = 18241590.

The previous prime is 18241549. The next prime is 18241607. The reversal of 18241591 is 19514281.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18241591 - 2¹⁹ = 17717303 is a prime.

It is a super-2 number, since 2×18241591² = 665511284422562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18241511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9120795 + 9120796.

It is an arithmetic number, because the mean of its divisors is an integer number (9120796).

Almost surely, 2^18241591 is an apocalyptic number.

18241591 is a deficient number, since it is larger than the sum of its proper divisors (1).

18241591 is an equidigital number, since it uses as much as digits as its factorization.

18241591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 31.

The square root of 18241591 is about 4271.0175602542. The cubic root of 18241591 is about 263.2414279861.

The spelling of 18241591 in words is "eighteen million, two hundred forty-one thousand, five hundred ninety-one".