1221202212121 has 8 divisors (see below), whose sum is σ = 1230551635104. Its totient is φ = 1211853202560.

The previous prime is 1221202212107. The next prime is 1221202212127. The reversal of 1221202212121 is 1212122021221.

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 1221202212121 - 2¹⁷ = 1221202081049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221202212127) 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, 8653690 + ... + 8793676.

It is an arithmetic number, because the mean of its divisors is an integer number (153818954388).

Almost surely, 2^{1221202212121} is an apocalyptic number.

It is an amenable number.

1221202212121 is a deficient number, since it is larger than the sum of its proper divisors (9349422983).

1221202212121 is a wasteful number, since it uses less digits than its factorization.

1221202212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206711.

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

Adding to 1221202212121 its reverse (1212122021221), we get a palindrome (2433324233342).

The spelling of 1221202212121 in words is "one trillion, two hundred twenty-one billion, two hundred two million, two hundred twelve thousand, one hundred twenty-one".