1220202109891 has 2 divisors, whose sum is σ = 1220202109892. Its totient is φ = 1220202109890.

The previous prime is 1220202109853. The next prime is 1220202109933. The reversal of 1220202109891 is 1989012020221.

It is a weak prime.

It is an emirp because it is prime and its reverse (1989012020221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1220202109891 - 2¹⁵ = 1220202077123 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1220202109891.

It is not a weakly prime, because it can be changed into another prime (1220202109831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610101054945 + 610101054946.

It is an arithmetic number, because the mean of its divisors is an integer number (610101054946).

Almost surely, 2^{1220202109891} is an apocalyptic number.

1220202109891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220202109891 is an equidigital number, since it uses as much as digits as its factorization.

1220202109891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 37.

The spelling of 1220202109891 in words is "one trillion, two hundred twenty billion, two hundred two million, one hundred nine thousand, eight hundred ninety-one".