1221120021021 has 16 divisors (see below), whose sum is σ = 1735097462784. Its totient is φ = 762117457904.

The previous prime is 1221120020969. The next prime is 1221120021083. The reversal of 1221120021021 is 1201200211221.

It is not a de Polignac number, because 1221120021021 - 2⁶ = 1221120020957 is a prime.

It is a super-2 number, since 2×1221120021021² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221120021221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188266881 + ... + 188273366.

It is an arithmetic number, because the mean of its divisors is an integer number (108443591424).

Almost surely, 2^{1221120021021} is an apocalyptic number.

It is an amenable number.

1221120021021 is a deficient number, since it is larger than the sum of its proper divisors (513977441763).

1221120021021 is a wasteful number, since it uses less digits than its factorization.

1221120021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376540320.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221120021021 its reverse (1201200211221), we get a palindrome (2422320232242).

The spelling of 1221120021021 in words is "one trillion, two hundred twenty-one billion, one hundred twenty million, twenty-one thousand, twenty-one".