166649449 has 2 divisors, whose sum is σ = 166649450. Its totient is φ = 166649448.

The previous prime is 166649447. The next prime is 166649471. The reversal of 166649449 is 944946661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 92775424 + 73874025 = 9632^2 + 8595^2 .

It is a cyclic number.

It is not a de Polignac number, because 166649449 - 2¹ = 166649447 is a prime.

Together with 166649447, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (166649447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83324724 + 83324725.

It is an arithmetic number, because the mean of its divisors is an integer number (83324725).

Almost surely, 2^166649449 is an apocalyptic number.

It is an amenable number.

166649449 is a deficient number, since it is larger than the sum of its proper divisors (1).

166649449 is an equidigital number, since it uses as much as digits as its factorization.

166649449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 49.

The square root of 166649449 is about 12909.2776327725. The cubic root of 166649449 is about 550.3022570023.

It can be divided in two parts, 1666 and 49449, that added together give a palindrome (51115).

The spelling of 166649449 in words is "one hundred sixty-six million, six hundred forty-nine thousand, four hundred forty-nine".