166642649 has 2 divisors, whose sum is σ = 166642650. Its totient is φ = 166642648.

The previous prime is 166642633. The next prime is 166642657. The reversal of 166642649 is 946246661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111408025 + 55234624 = 10555^2 + 7432^2 .

It is a cyclic number.

It is not a de Polignac number, because 166642649 - 2⁴ = 166642633 is a prime.

It is not a weakly prime, because it can be changed into another prime (166642699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83321324 + 83321325.

It is an arithmetic number, because the mean of its divisors is an integer number (83321325).

Almost surely, 2^166642649 is an apocalyptic number.

It is an amenable number.

166642649 is a deficient number, since it is larger than the sum of its proper divisors (1).

166642649 is an equidigital number, since it uses as much as digits as its factorization.

166642649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 44.

The square root of 166642649 is about 12909.0142536136. The cubic root of 166642649 is about 550.2947720165.

The spelling of 166642649 in words is "one hundred sixty-six million, six hundred forty-two thousand, six hundred forty-nine".