1666164725855 has 16 divisors (see below), whose sum is σ = 2285048314944. Its totient is φ = 1142501752320.

The previous prime is 1666164725807. The next prime is 1666164725857. The reversal of 1666164725855 is 5585274616661.

It is not a de Polignac number, because 1666164725855 - 2⁶ = 1666164725791 is a prime.

It is a super-2 number, since 2×1666164725855² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666164725857) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5110535 + ... + 5426775.

It is an arithmetic number, because the mean of its divisors is an integer number (142815519684).

Almost surely, 2^{1666164725855} is an apocalyptic number.

1666164725855 is a deficient number, since it is larger than the sum of its proper divisors (618883589089).

1666164725855 is a wasteful number, since it uses less digits than its factorization.

1666164725855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 466786.

The product of its digits is 72576000, while the sum is 62.

The spelling of 1666164725855 in words is "one trillion, six hundred sixty-six billion, one hundred sixty-four million, seven hundred twenty-five thousand, eight hundred fifty-five".