18536261 has 2 divisors, whose sum is σ = 18536262. Its totient is φ = 18536260.

The previous prime is 18536201. The next prime is 18536263. The reversal of 18536261 is 16263581.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16859236 + 1677025 = 4106^2 + 1295^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18536261 is a prime.

It is a Sophie Germain prime.

Together with 18536263, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18536263) 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, 9268130 + 9268131.

It is an arithmetic number, because the mean of its divisors is an integer number (9268131).

Almost surely, 2^18536261 is an apocalyptic number.

It is an amenable number.

18536261 is a deficient number, since it is larger than the sum of its proper divisors (1).

18536261 is an equidigital number, since it uses as much as digits as its factorization.

18536261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 32.

The square root of 18536261 is about 4305.3758256394. The cubic root of 18536261 is about 264.6513083262.

The spelling of 18536261 in words is "eighteen million, five hundred thirty-six thousand, two hundred sixty-one".