23181491 has 2 divisors, whose sum is σ = 23181492. Its totient is φ = 23181490.

The previous prime is 23181461. The next prime is 23181503. The reversal of 23181491 is 19418132.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23181491 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (23181451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11590745 + 11590746.

It is an arithmetic number, because the mean of its divisors is an integer number (11590746).

Almost surely, 2^23181491 is an apocalyptic number.

23181491 is a deficient number, since it is larger than the sum of its proper divisors (1).

23181491 is an equidigital number, since it uses as much as digits as its factorization.

23181491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 29.

The square root of 23181491 is about 4814.7160871644. The cubic root of 23181491 is about 285.1327626039.

The spelling of 23181491 in words is "twenty-three million, one hundred eighty-one thousand, four hundred ninety-one".