166577768043989 has 4 divisors (see below), whose sum is σ = 168449428359180. Its totient is φ = 164706107728800.

The previous prime is 166577768043959. The next prime is 166577768044007. The reversal of 166577768043989 is 989340867775661.

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

It can be written as a sum of positive squares in 2 ways, for example, as 19927072800625 + 146650695243364 = 4463975^2 + 12109942^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166577768043989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166577768043989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166577768043959) 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, 935830157462 + ... + 935830157639.

It is an arithmetic number, because the mean of its divisors is an integer number (42112357089795).

Almost surely, 2^{166577768043989} is an apocalyptic number.

It is an amenable number.

166577768043989 is a deficient number, since it is larger than the sum of its proper divisors (1871660315191).

166577768043989 is an equidigital number, since it uses as much as digits as its factorization.

166577768043989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1871660315190.

The product of its (nonzero) digits is 23044331520, while the sum is 86.

The spelling of 166577768043989 in words is "one hundred sixty-six trillion, five hundred seventy-seven billion, seven hundred sixty-eight million, forty-three thousand, nine hundred eighty-nine".