1221312232105 has 16 divisors (see below), whose sum is σ = 1675077053184. Its totient is φ = 837403963200.

The previous prime is 1221312232079. The next prime is 1221312232111. The reversal of 1221312232105 is 5012322131221.

It is not a de Polignac number, because 1221312232105 - 2¹¹ = 1221312230057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221312232105.

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, 957846 + ... + 1833055.

It is an arithmetic number, because the mean of its divisors is an integer number (104692315824).

Almost surely, 2^{1221312232105} is an apocalyptic number.

It is an amenable number.

1221312232105 is a deficient number, since it is larger than the sum of its proper divisors (453764821079).

1221312232105 is a wasteful number, since it uses less digits than its factorization.

1221312232105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2803416.

The product of its (nonzero) digits is 1440, while the sum is 25.

Adding to 1221312232105 its reverse (5012322131221), we get a palindrome (6233634363326).

The spelling of 1221312232105 in words is "one trillion, two hundred twenty-one billion, three hundred twelve million, two hundred thirty-two thousand, one hundred five".