166443551 has 2 divisors, whose sum is σ = 166443552. Its totient is φ = 166443550.

The previous prime is 166443547. The next prime is 166443569. The reversal of 166443551 is 155344661.

It is a weak prime.

It is an emirp because it is prime and its reverse (155344661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166443551 - 2² = 166443547 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166443521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83221775 + 83221776.

It is an arithmetic number, because the mean of its divisors is an integer number (83221776).

Almost surely, 2^166443551 is an apocalyptic number.

166443551 is a deficient number, since it is larger than the sum of its proper divisors (1).

166443551 is an equidigital number, since it uses as much as digits as its factorization.

166443551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43200, while the sum is 35.

The square root of 166443551 is about 12901.3003608163. The cubic root of 166443551 is about 550.0755279198.

The spelling of 166443551 in words is "one hundred sixty-six million, four hundred forty-three thousand, five hundred fifty-one".