1221110021021 has 4 divisors (see below), whose sum is σ = 1332120022944. Its totient is φ = 1110100019100.

The previous prime is 1221110020997. The next prime is 1221110021057. The reversal of 1221110021021 is 1201200111221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1221110021021 - 2⁶ = 1221110020957 is a prime.

It is a super-2 number, since 2×1221110021021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221110020987 and 1221110021005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221110021221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55505000945 + ... + 55505000966.

It is an arithmetic number, because the mean of its divisors is an integer number (333030005736).

Almost surely, 2^{1221110021021} is an apocalyptic number.

1221110021021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221110021021 is a deficient number, since it is larger than the sum of its proper divisors (111010001923).

1221110021021 is a wasteful number, since it uses less digits than its factorization.

1221110021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111010001922.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221110021021 its reverse (1201200111221), we get a palindrome (2422310132242).

The spelling of 1221110021021 in words is "one trillion, two hundred twenty-one billion, one hundred ten million, twenty-one thousand, twenty-one".