9666220261 has 4 divisors (see below), whose sum is σ = 9672214572. Its totient is φ = 9660225952.

The previous prime is 9666220243. The next prime is 9666220279. The reversal of 9666220261 is 1620226669.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (9666220243) and next prime (9666220279).

It can be written as a sum of positive squares in 2 ways, for example, as 7414243236 + 2251977025 = 86106^2 + 47455^2 .

It is a cyclic number.

It is not a de Polignac number, because 9666220261 - 2⁷ = 9666220133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9666220211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2994736 + ... + 2997961.

It is an arithmetic number, because the mean of its divisors is an integer number (2418053643).

Almost surely, 2^9666220261 is an apocalyptic number.

It is an amenable number.

9666220261 is a deficient number, since it is larger than the sum of its proper divisors (5994311).

9666220261 is a wasteful number, since it uses less digits than its factorization.

9666220261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5994310.

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 9666220261 is about 98316.9378133798. The cubic root of 9666220261 is about 2130.1927177638.

The spelling of 9666220261 in words is "nine billion, six hundred sixty-six million, two hundred twenty thousand, two hundred sixty-one".