18479521 has 2 divisors, whose sum is σ = 18479522. Its totient is φ = 18479520.

The previous prime is 18479509. The next prime is 18479537. The reversal of 18479521 is 12597481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16120225 + 2359296 = 4015^2 + 1536^2 .

It is a cyclic number.

It is not a de Polignac number, because 18479521 - 2⁷ = 18479393 is a prime.

It is not a weakly prime, because it can be changed into another prime (18479581) 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, 9239760 + 9239761.

It is an arithmetic number, because the mean of its divisors is an integer number (9239761).

Almost surely, 2^18479521 is an apocalyptic number.

It is an amenable number.

18479521 is a deficient number, since it is larger than the sum of its proper divisors (1).

18479521 is an equidigital number, since it uses as much as digits as its factorization.

18479521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 37.

The square root of 18479521 is about 4298.7813389378. The cubic root of 18479521 is about 264.3809973732.

The spelling of 18479521 in words is "eighteen million, four hundred seventy-nine thousand, five hundred twenty-one".