111221021021 has 4 divisors (see below), whose sum is σ = 121332022944. Its totient is φ = 101110019100.

The previous prime is 111221020961. The next prime is 111221021029. The reversal of 111221021021 is 120120122111.

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 a de Polignac number, because none of the positive numbers 2^k-111221021021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111221020987 and 111221021005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111221021029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5055500945 + ... + 5055500966.

It is an arithmetic number, because the mean of its divisors is an integer number (30333005736).

Almost surely, 2^111221021021 is an apocalyptic number.

111221021021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111221021021 is a deficient number, since it is larger than the sum of its proper divisors (10111001923).

111221021021 is a wasteful number, since it uses less digits than its factorization.

111221021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10111001922.

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

Adding to 111221021021 its reverse (120120122111), we get a palindrome (231341143132).

The spelling of 111221021021 in words is "one hundred eleven billion, two hundred twenty-one million, twenty-one thousand, twenty-one".