1221101221986 has 24 divisors (see below), whose sum is σ = 2646182318364. Its totient is φ = 406962509280.

The previous prime is 1221101221919. The next prime is 1221101221987. The reversal of 1221101221986 is 6891221011221.

It can be written as a sum of positive squares in 2 ways, for example, as 1124513905761 + 96587316225 = 1060431^2 + 310785^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1221101221986.

It is not an unprimeable number, because it can be changed into a prime (1221101221987) 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, 5830185 + ... + 6035996.

Almost surely, 2^{1221101221986} is an apocalyptic number.

1221101221986 is an abundant number, since it is smaller than the sum of its proper divisors (1425081096378).

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

1221101221986 is a wasteful number, since it uses less digits than its factorization.

1221101221986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11871906 (or 11871903 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The spelling of 1221101221986 in words is "one trillion, two hundred twenty-one billion, one hundred one million, two hundred twenty-one thousand, nine hundred eighty-six".