1211100021988 has 24 divisors (see below), whose sum is σ = 2247565646592. Its totient is φ = 569048521344.

The previous prime is 1211100021979. The next prime is 1211100022009. The reversal of 1211100021988 is 8891200011121.

It is a Harshad number since it is a multiple of its sum of digits (34).

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 7 ways as a sum of consecutive naturals, for example, 13719756 + ... + 13807747.

It is an arithmetic number, because the mean of its divisors is an integer number (93648568608).

Almost surely, 2^{1211100021988} is an apocalyptic number.

It is an amenable number.

1211100021988 is a deficient number, since it is larger than the sum of its proper divisors (1036465624604).

1211100021988 is a wasteful number, since it uses less digits than its factorization.

1211100021988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27528171 (or 27528169 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 34.

The spelling of 1211100021988 in words is "one trillion, two hundred eleven billion, one hundred million, twenty-one thousand, nine hundred eighty-eight".