9866222781 has 12 divisors (see below), whose sum is σ = 13593010176. Its totient is φ = 6365303160.

The previous prime is 9866222759. The next prime is 9866222783. The reversal of 9866222781 is 1872226689.

It is not a de Polignac number, because 9866222781 - 2¹¹ = 9866220733 is a prime.

It is a super-2 number, since 2×9866222781² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9866222783) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1708221 + ... + 1713986.

It is an arithmetic number, because the mean of its divisors is an integer number (1132750848).

Almost surely, 2^9866222781 is an apocalyptic number.

It is an amenable number.

9866222781 is a deficient number, since it is larger than the sum of its proper divisors (3726787395).

9866222781 is a wasteful number, since it uses less digits than its factorization.

9866222781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3422272 (or 3422241 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 51.

The square root of 9866222781 is about 99328.8617723973. The cubic root of 9866222781 is about 2144.7843854974.

The spelling of 9866222781 in words is "nine billion, eight hundred sixty-six million, two hundred twenty-two thousand, seven hundred eighty-one".