18139633 has 2 divisors, whose sum is σ = 18139634. Its totient is φ = 18139632.

The previous prime is 18139613. The next prime is 18139711. The reversal of 18139633 is 33693181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12341169 + 5798464 = 3513^2 + 2408^2 .

It is a cyclic number.

It is not a de Polignac number, because 18139633 - 2⁵ = 18139601 is a prime.

It is not a weakly prime, because it can be changed into another prime (18139613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9069816 + 9069817.

It is an arithmetic number, because the mean of its divisors is an integer number (9069817).

Almost surely, 2^18139633 is an apocalyptic number.

It is an amenable number.

18139633 is a deficient number, since it is larger than the sum of its proper divisors (1).

18139633 is an equidigital number, since it uses as much as digits as its factorization.

18139633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 34.

The square root of 18139633 is about 4259.0648034516. The cubic root of 18139633 is about 262.7500649556.

The spelling of 18139633 in words is "eighteen million, one hundred thirty-nine thousand, six hundred thirty-three".