1221041535505 has 16 divisors (see below), whose sum is σ = 1599222642048. Its totient is φ = 887603392000.

The previous prime is 1221041535491. The next prime is 1221041535541. The reversal of 1221041535505 is 5055351401221.

It is not a de Polignac number, because 1221041535505 - 2³⁵ = 1186681797137 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5219701 + ... + 5448610.

It is an arithmetic number, because the mean of its divisors is an integer number (99951415128).

Almost surely, 2^{1221041535505} is an apocalyptic number.

It is an amenable number.

1221041535505 is a deficient number, since it is larger than the sum of its proper divisors (378181106543).

1221041535505 is a wasteful number, since it uses less digits than its factorization.

1221041535505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10670408.

The product of its (nonzero) digits is 30000, while the sum is 34.

Adding to 1221041535505 its reverse (5055351401221), we get a palindrome (6276392936726).

The spelling of 1221041535505 in words is "one trillion, two hundred twenty-one billion, forty-one million, five hundred thirty-five thousand, five hundred five".