22001221202121 has 56 divisors (see below), whose sum is σ = 38468503996800. Its totient is φ = 12572126258328.

The previous prime is 22001221202099. The next prime is 22001221202173. The reversal of 22001221202121 is 12120212210022.

It is a happy number.

22001221202121 is a `hidden beast` number, since 220 + 0 + 1 + 221 + 202 + 1 + 21 = 666.

It is not a de Polignac number, because 22001221202121 - 2¹³ = 22001221193929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22001221202094 and 22001221202103.

It is not an unprimeable number, because it can be changed into a prime (22001221202021) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 43744125 + ... + 44244218.

Almost surely, 2^{22001221202121} is an apocalyptic number.

22001221202121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

22001221202121 is a deficient number, since it is larger than the sum of its proper divisors (16467282794679).

22001221202121 is an frugal number, since it uses more digits than its factorization.

22001221202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87988382 (or 87988353 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 22001221202121 its reverse (12120212210022), we get a palindrome (34121433412143).

The spelling of 22001221202121 in words is "twenty-two trillion, one billion, two hundred twenty-one million, two hundred two thousand, one hundred twenty-one".