1666061279 has 4 divisors (see below), whose sum is σ = 1673400984. Its totient is φ = 1658721576.

The previous prime is 1666061269. The next prime is 1666061291. The reversal of 1666061279 is 9721606661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1666061279 - 2⁴ = 1666061263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666061209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3669512 + ... + 3669965.

It is an arithmetic number, because the mean of its divisors is an integer number (418350246).

Almost surely, 2^1666061279 is an apocalyptic number.

1666061279 is a deficient number, since it is larger than the sum of its proper divisors (7339705).

1666061279 is an equidigital number, since it uses as much as digits as its factorization.

1666061279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7339704.

The product of its (nonzero) digits is 163296, while the sum is 44.

The square root of 1666061279 is about 40817.4139185716. The cubic root of 1666061279 is about 1185.4875308229.

The spelling of 1666061279 in words is "one billion, six hundred sixty-six million, sixty-one thousand, two hundred seventy-nine".