18027661 has 2 divisors, whose sum is σ = 18027662. Its totient is φ = 18027660.

The previous prime is 18027643. The next prime is 18027673. The reversal of 18027661 is 16672081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17015625 + 1012036 = 4125^2 + 1006^2 .

It is a cyclic number.

It is not a de Polignac number, because 18027661 - 2⁷ = 18027533 is a prime.

It is a super-2 number, since 2×18027661² = 649993122261842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18027631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9013830 + 9013831.

It is an arithmetic number, because the mean of its divisors is an integer number (9013831).

Almost surely, 2^18027661 is an apocalyptic number.

It is an amenable number.

18027661 is a deficient number, since it is larger than the sum of its proper divisors (1).

18027661 is an equidigital number, since it uses as much as digits as its factorization.

18027661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 18027661 is about 4245.8993158105. The cubic root of 18027661 is about 262.2083157651.

The spelling of 18027661 in words is "eighteen million, twenty-seven thousand, six hundred sixty-one".