18669731 has 2 divisors, whose sum is σ = 18669732. Its totient is φ = 18669730.

The previous prime is 18669713. The next prime is 18669737. The reversal of 18669731 is 13796681.

Together with previous prime (18669713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (13796681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18669731 - 2¹⁴ = 18653347 is a prime.

It is a super-2 number, since 2×18669731² = 697117711224722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18669737) 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, 9334865 + 9334866.

It is an arithmetic number, because the mean of its divisors is an integer number (9334866).

Almost surely, 2^18669731 is an apocalyptic number.

18669731 is a deficient number, since it is larger than the sum of its proper divisors (1).

18669731 is an equidigital number, since it uses as much as digits as its factorization.

18669731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 41.

The square root of 18669731 is about 4320.8484120598. The cubic root of 18669731 is about 265.2849953961.

The spelling of 18669731 in words is "eighteen million, six hundred sixty-nine thousand, seven hundred thirty-one".