18660221225731 has 2 divisors, whose sum is σ = 18660221225732. Its totient is φ = 18660221225730.

The previous prime is 18660221225713. The next prime is 18660221225741. The reversal of 18660221225731 is 13752212206681.

Together with previous prime (18660221225713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18660221225731 - 2⁷ = 18660221225603 is a prime.

It is a super-2 number, since 2×18660221225731² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18660221225741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9330110612865 + 9330110612866.

It is an arithmetic number, because the mean of its divisors is an integer number (9330110612866).

Almost surely, 2^{18660221225731} is an apocalyptic number.

18660221225731 is a deficient number, since it is larger than the sum of its proper divisors (1).

18660221225731 is an equidigital number, since it uses as much as digits as its factorization.

18660221225731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 18660221225731 in words is "eighteen trillion, six hundred sixty billion, two hundred twenty-one million, two hundred twenty-five thousand, seven hundred thirty-one".