1221211212099 has 16 divisors (see below), whose sum is σ = 1746319910400. Its totient is φ = 756738624096.

The previous prime is 1221211211959. The next prime is 1221211212187. The reversal of 1221211212099 is 9902121121221.

It is not a de Polignac number, because 1221211212099 - 2¹² = 1221211208003 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221211292099) 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 15 ways as a sum of consecutive naturals, for example, 202117339 + ... + 202123380.

It is an arithmetic number, because the mean of its divisors is an integer number (109144994400).

Almost surely, 2^{1221211212099} is an apocalyptic number.

1221211212099 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1221211212099 is a deficient number, since it is larger than the sum of its proper divisors (525108698301).

1221211212099 is a wasteful number, since it uses less digits than its factorization.

1221211212099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404240794.

The product of its (nonzero) digits is 2592, while the sum is 33.

The spelling of 1221211212099 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, two hundred twelve thousand, ninety-nine".