18505969 has 2 divisors, whose sum is σ = 18505970. Its totient is φ = 18505968.

The previous prime is 18505939. The next prime is 18506021. The reversal of 18505969 is 96950581.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18386944 + 119025 = 4288^2 + 345^2 .

It is a cyclic number.

It is not a de Polignac number, because 18505969 - 2⁹ = 18505457 is a prime.

It is a super-2 number, since 2×18505969² = 684941777257922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18505909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9252984 + 9252985.

It is an arithmetic number, because the mean of its divisors is an integer number (9252985).

Almost surely, 2^18505969 is an apocalyptic number.

It is an amenable number.

18505969 is a deficient number, since it is larger than the sum of its proper divisors (1).

18505969 is an equidigital number, since it uses as much as digits as its factorization.

18505969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 97200, while the sum is 43.

The square root of 18505969 is about 4301.8564597160. The cubic root of 18505969 is about 264.5070651329.

It can be divided in two parts, 1850 and 5969, that multiplied together give a triangular number (11042650 = T₄₆₉₉).

The spelling of 18505969 in words is "eighteen million, five hundred five thousand, nine hundred sixty-nine".