166644641 has 2 divisors, whose sum is σ = 166644642. Its totient is φ = 166644640.

The previous prime is 166644617. The next prime is 166644677. The reversal of 166644641 is 146446661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163737616 + 2907025 = 12796^2 + 1705^2 .

It is a cyclic number.

It is not a de Polignac number, because 166644641 - 2¹⁴ = 166628257 is a prime.

It is equal to p_9325829 and since 166644641 and 9325829 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 166644595 and 166644604.

It is not a weakly prime, because it can be changed into another prime (166644601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83322320 + 83322321.

It is an arithmetic number, because the mean of its divisors is an integer number (83322321).

Almost surely, 2^166644641 is an apocalyptic number.

It is an amenable number.

166644641 is a deficient number, since it is larger than the sum of its proper divisors (1).

166644641 is an equidigital number, since it uses as much as digits as its factorization.

166644641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 38.

The square root of 166644641 is about 12909.0914087708. The cubic root of 166644641 is about 550.2969646981.

The spelling of 166644641 in words is "one hundred sixty-six million, six hundred forty-four thousand, six hundred forty-one".