1665166651 has 2 divisors, whose sum is σ = 1665166652. Its totient is φ = 1665166650.

The previous prime is 1665166603. The next prime is 1665166681. The reversal of 1665166651 is 1566615661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1665166651 - 2¹⁷ = 1665035579 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1665166598 and 1665166607.

It is not a weakly prime, because it can be changed into another prime (1665166681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832583325 + 832583326.

It is an arithmetic number, because the mean of its divisors is an integer number (832583326).

Almost surely, 2^1665166651 is an apocalyptic number.

1665166651 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665166651 is an equidigital number, since it uses as much as digits as its factorization.

1665166651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 194400, while the sum is 43.

The square root of 1665166651 is about 40806.4535459773. The cubic root of 1665166651 is about 1185.2753016888.

The spelling of 1665166651 in words is "one billion, six hundred sixty-five million, one hundred sixty-six thousand, six hundred fifty-one".