1666027481 has 2 divisors, whose sum is σ = 1666027482. Its totient is φ = 1666027480.

The previous prime is 1666027469. The next prime is 1666027501. The reversal of 1666027481 is 1847206661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1414963456 + 251064025 = 37616^2 + 15845^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666027481 - 2⁶ = 1666027417 is a prime.

It is a super-2 number, since 2×1666027481² = 5551295134894410722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1666023481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833013740 + 833013741.

It is an arithmetic number, because the mean of its divisors is an integer number (833013741).

Almost surely, 2^1666027481 is an apocalyptic number.

It is an amenable number.

1666027481 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666027481 is an equidigital number, since it uses as much as digits as its factorization.

1666027481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 1666027481 is about 40816.9999020016. Note that the first 4 decimals coincide. The cubic root of 1666027481 is about 1185.4795144354.

The spelling of 1666027481 in words is "one billion, six hundred sixty-six million, twenty-seven thousand, four hundred eighty-one".