166531444405061 has 4 divisors (see below), whose sum is σ = 166907361887232. Its totient is φ = 166155526922892.

The previous prime is 166531444405049. The next prime is 166531444405063. The reversal of 166531444405061 is 160504444135661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 166531444405061 - 2²⁶ = 166531377296197 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 (166531444405063) 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, 187958740421 + ... + 187958741306.

It is an arithmetic number, because the mean of its divisors is an integer number (41726840471808).

Almost surely, 2^{166531444405061} is an apocalyptic number.

It is an amenable number.

166531444405061 is a deficient number, since it is larger than the sum of its proper divisors (375917482171).

166531444405061 is an equidigital number, since it uses as much as digits as its factorization.

166531444405061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375917482170.

The product of its (nonzero) digits is 4147200, while the sum is 50.

The spelling of 166531444405061 in words is "one hundred sixty-six trillion, five hundred thirty-one billion, four hundred forty-four million, four hundred five thousand, sixty-one".