18621013 has 2 divisors, whose sum is σ = 18621014. Its totient is φ = 18621012.

The previous prime is 18620999. The next prime is 18621017. The reversal of 18621013 is 31012681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18601969 + 19044 = 4313^2 + 138^2 .

It is a cyclic number.

It is not a de Polignac number, because 18621013 - 2⁵ = 18620981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18621017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9310506 + 9310507.

It is an arithmetic number, because the mean of its divisors is an integer number (9310507).

Almost surely, 2^18621013 is an apocalyptic number.

It is an amenable number.

18621013 is a deficient number, since it is larger than the sum of its proper divisors (1).

18621013 is an equidigital number, since it uses as much as digits as its factorization.

18621013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 18621013 is about 4315.2071792673. The cubic root of 18621013 is about 265.0540438014.

Adding to 18621013 its reverse (31012681), we get a palindrome (49633694).

The spelling of 18621013 in words is "eighteen million, six hundred twenty-one thousand, thirteen".