20121221099 has 8 divisors (see below), whose sum is σ = 23163534048. Its totient is φ = 17120871360.

The previous prime is 20121221041. The next prime is 20121221117. The reversal of 20121221099 is 99012212102.

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

It is a cyclic number.

It is not a de Polignac number, because 20121221099 - 2²⁴ = 20104443883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20121224099) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10489772 + ... + 10491689.

It is an arithmetic number, because the mean of its divisors is an integer number (2895441756).

Almost surely, 2^20121221099 is an apocalyptic number.

20121221099 is a deficient number, since it is larger than the sum of its proper divisors (3042312949).

20121221099 is a wasteful number, since it uses less digits than its factorization.

20121221099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20981605.

The product of its (nonzero) digits is 1296, while the sum is 29.

The spelling of 20121221099 in words is "twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, ninety-nine".