18121633 has 2 divisors, whose sum is σ = 18121634. Its totient is φ = 18121632.

The previous prime is 18121613. The next prime is 18121651. The reversal of 18121633 is 33612181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17740944 + 380689 = 4212^2 + 617^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18121633 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18121598 and 18121607.

It is not a weakly prime, because it can be changed into another prime (18121603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9060816 + 9060817.

It is an arithmetic number, because the mean of its divisors is an integer number (9060817).

Almost surely, 2^18121633 is an apocalyptic number.

It is an amenable number.

18121633 is a deficient number, since it is larger than the sum of its proper divisors (1).

18121633 is an equidigital number, since it uses as much as digits as its factorization.

18121633 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 18121633 is about 4256.9511390196. The cubic root of 18121633 is about 262.6631270262.

The spelling of 18121633 in words is "eighteen million, one hundred twenty-one thousand, six hundred thirty-three".