1221210222121 has 8 divisors (see below), whose sum is σ = 1226461116384. Its totient is φ = 1215962388000.

The previous prime is 1221210222103. The next prime is 1221210222203. The reversal of 1221210222121 is 1212220121221.

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 1221210222121 - 2¹¹ = 1221210220073 is a prime.

It is a super-2 number, since 2×1221210222121² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221210222101) 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, 36621 + ... + 1563253.

It is an arithmetic number, because the mean of its divisors is an integer number (153307639548).

Almost surely, 2^{1221210222121} is an apocalyptic number.

It is an amenable number.

1221210222121 is a deficient number, since it is larger than the sum of its proper divisors (5250894263).

1221210222121 is a wasteful number, since it uses less digits than its factorization.

1221210222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1530071.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1221210222121 its reverse (1212220121221), we get a palindrome (2433430343342).

The spelling of 1221210222121 in words is "one trillion, two hundred twenty-one billion, two hundred ten million, two hundred twenty-two thousand, one hundred twenty-one".