1666163501 has 2 divisors, whose sum is σ = 1666163502. Its totient is φ = 1666163500.

The previous prime is 1666163407. The next prime is 1666163533. The reversal of 1666163501 is 1053616661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1298521225 + 367642276 = 36035^2 + 19174^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666163501 - 2²⁶ = 1599054637 is a prime.

It is a super-2 number, since 2×1666163501² = 5552201624129154002, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666163581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833081750 + 833081751.

It is an arithmetic number, because the mean of its divisors is an integer number (833081751).

Almost surely, 2^1666163501 is an apocalyptic number.

It is an amenable number.

1666163501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666163501 is an equidigital number, since it uses as much as digits as its factorization.

1666163501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 1666163501 is about 40818.6660855055. Note that the first 3 decimals coincide. The cubic root of 1666163501 is about 1185.5117757150.

The spelling of 1666163501 in words is "one billion, six hundred sixty-six million, one hundred sixty-three thousand, five hundred one".