1666027501 has 2 divisors, whose sum is σ = 1666027502. Its totient is φ = 1666027500.

The previous prime is 1666027481. The next prime is 1666027537. The reversal of 1666027501 is 1057206661.

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., 1440126601 + 225900900 = 37949^2 + 15030^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666027501 - 2⁵ = 1666027469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666027301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833013750 + 833013751.

It is an arithmetic number, because the mean of its divisors is an integer number (833013751).

Almost surely, 2^1666027501 is an apocalyptic number.

It is an amenable number.

1666027501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666027501 is an equidigital number, since it uses as much as digits as its factorization.

1666027501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 1666027501 is about 40817.0001469976. Note that the first 3 decimals coincide. The cubic root of 1666027501 is about 1185.4795191791.

The spelling of 1666027501 in words is "one billion, six hundred sixty-six million, twenty-seven thousand, five hundred one".