9966649 has 27 divisors (see below), whose sum is σ = 13062063. Its totient is φ = 7576800.

The previous prime is 9966643. The next prime is 9966667. The reversal of 9966649 is 9466699.

It is a happy number.

The square root of 9966649 is 3157.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 480249 + 9486400 = 693^2 + 3080^2 .

It is not a de Polignac number, because 9966649 - 2⁹ = 9966137 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (9966643) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 243069 + ... + 243109.

Almost surely, 2^9966649 is an apocalyptic number.

9966649 is the 3157-th square number.

9966649 is the 1579-th centered octagonal number.

It is an amenable number.

9966649 is a deficient number, since it is larger than the sum of its proper divisors (3095414).

9966649 is a wasteful number, since it uses less digits than its factorization.

9966649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 59 counting only the distinct ones).

The product of its digits is 629856, while the sum is 49.

The cubic root of 9966649 is about 215.2036937427.

Multiplying 9966649 by its sum of digits (49), we get a square (488365801 = 22099²).

9966649 divided by its sum of digits (49) gives a square (203401 = 451²).

The spelling of 9966649 in words is "nine million, nine hundred sixty-six thousand, six hundred forty-nine".