1221201111021 has 8 divisors (see below), whose sum is σ = 1672275395424. Its totient is φ = 792130450320.

The previous prime is 1221201110999. The next prime is 1221201111029. The reversal of 1221201111021 is 1201111021221.

It is a happy number.

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

It is not a de Polignac number, because 1221201111021 - 2⁵ = 1221201110989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221201111029) 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, 5500905795 + ... + 5500906016.

It is an arithmetic number, because the mean of its divisors is an integer number (209034424428).

Almost surely, 2^{1221201111021} is an apocalyptic number.

It is an amenable number.

1221201111021 is a deficient number, since it is larger than the sum of its proper divisors (451074284403).

1221201111021 is a wasteful number, since it uses less digits than its factorization.

1221201111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11001811851.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221201111021 its reverse (1201111021221), we get a palindrome (2422312132242).

The spelling of 1221201111021 in words is "one trillion, two hundred twenty-one billion, two hundred one million, one hundred eleven thousand, twenty-one".