1211111221986 has 48 divisors (see below), whose sum is σ = 2782055421600. Its totient is φ = 379704677184.

The previous prime is 1211111221981. The next prime is 1211111221987. The reversal of 1211111221986 is 6891221111121.

It is a self number, because there is not a number n which added to its sum of digits gives 1211111221986.

It is not an unprimeable number, because it can be changed into a prime (1211111221981) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12690811 + ... + 12785886.

It is an arithmetic number, because the mean of its divisors is an integer number (57959487950).

Almost surely, 2^{1211111221986} is an apocalyptic number.

1211111221986 is an abundant number, since it is smaller than the sum of its proper divisors (1570944199614).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211111221986 is a wasteful number, since it uses less digits than its factorization.

1211111221986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25476863 (or 25476860 counting only the distinct ones).

The product of its digits is 3456, while the sum is 36.

The spelling of 1211111221986 in words is "one trillion, two hundred eleven billion, one hundred eleven million, two hundred twenty-one thousand, nine hundred eighty-six".