1666498979 has 2 divisors, whose sum is σ = 1666498980. Its totient is φ = 1666498978.

The previous prime is 1666498963. The next prime is 1666499011. The reversal of 1666498979 is 9798946661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666498979 - 2⁴ = 1666498963 is a prime.

It is not a weakly prime, because it can be changed into another prime (1666498909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833249489 + 833249490.

It is an arithmetic number, because the mean of its divisors is an integer number (833249490).

Almost surely, 2^1666498979 is an apocalyptic number.

1666498979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666498979 is an equidigital number, since it uses as much as digits as its factorization.

1666498979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35271936, while the sum is 65.

The square root of 1666498979 is about 40822.7752486281. The cubic root of 1666498979 is about 1185.5913370205.

The spelling of 1666498979 in words is "one billion, six hundred sixty-six million, four hundred ninety-eight thousand, nine hundred seventy-nine".