1221281036889 has 8 divisors (see below), whose sum is σ = 1628392446240. Its totient is φ = 814178492736.

The previous prime is 1221281036839. The next prime is 1221281036903. The reversal of 1221281036889 is 9886301821221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221281036889 - 2⁷ = 1221281036761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221281036819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1887904 + ... + 2450865.

It is an arithmetic number, because the mean of its divisors is an integer number (203549055780).

Almost surely, 2^{1221281036889} is an apocalyptic number.

It is an amenable number.

1221281036889 is a deficient number, since it is larger than the sum of its proper divisors (407111409351).

1221281036889 is an equidigital number, since it uses as much as digits as its factorization.

1221281036889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4432599.

The product of its (nonzero) digits is 663552, while the sum is 51.

The spelling of 1221281036889 in words is "one trillion, two hundred twenty-one billion, two hundred eighty-one million, thirty-six thousand, eight hundred eighty-nine".