1221131020159 has 4 divisors (see below), whose sum is σ = 1228908924904. Its totient is φ = 1213353115416.

The previous prime is 1221131020157. The next prime is 1221131020181. The reversal of 1221131020159 is 9510201311221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221131020159 - 2¹ = 1221131020157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221131020157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3888952137 + ... + 3888952450.

It is an arithmetic number, because the mean of its divisors is an integer number (307227231226).

Almost surely, 2^{1221131020159} is an apocalyptic number.

1221131020159 is a deficient number, since it is larger than the sum of its proper divisors (7777904745).

1221131020159 is an equidigital number, since it uses as much as digits as its factorization.

1221131020159 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7777904744.

The product of its (nonzero) digits is 1080, while the sum is 28.

The spelling of 1221131020159 in words is "one trillion, two hundred twenty-one billion, one hundred thirty-one million, twenty thousand, one hundred fifty-nine".