1221110999966 has 24 divisors (see below), whose sum is σ = 2168190102792. Its totient is φ = 512354264400.

The previous prime is 1221110999951. The next prime is 1221111000013. The reversal of 1221110999966 is 6699990111221.

It is a super-2 number, since 2×1221110999966² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 194070440 + ... + 194076731.

It is an arithmetic number, because the mean of its divisors is an integer number (90341254283).

Almost surely, 2^{1221110999966} is an apocalyptic number.

1221110999966 is a deficient number, since it is larger than the sum of its proper divisors (947079102826).

1221110999966 is a wasteful number, since it uses less digits than its factorization.

1221110999966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388147208 (or 388147197 counting only the distinct ones).

The product of its (nonzero) digits is 944784, while the sum is 56.

The spelling of 1221110999966 in words is "one trillion, two hundred twenty-one billion, one hundred ten million, nine hundred ninety-nine thousand, nine hundred sixty-six".