121021111000021 has 4 divisors (see below), whose sum is σ = 121549587467500. Its totient is φ = 120492634532544.

The previous prime is 121021110999949. The next prime is 121021111000159. The reversal of 121021111000021 is 120000111120121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45474940607121 + 75546170392900 = 6743511^2 + 8691730^2 .

It is a cyclic number.

It is not a de Polignac number, because 121021111000021 - 2¹⁷ = 121021110868949 is a prime.

It is a super-2 number, since 2×121021111000021² (a number of 29 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 = 121021110999965 and 121021111000010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121021111000421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264238233396 + ... + 264238233853.

It is an arithmetic number, because the mean of its divisors is an integer number (30387396866875).

Almost surely, 2^{121021111000021} is an apocalyptic number.

It is an amenable number.

121021111000021 is a deficient number, since it is larger than the sum of its proper divisors (528476467479).

121021111000021 is an equidigital number, since it uses as much as digits as its factorization.

121021111000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528476467478.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 121021111000021 its reverse (120000111120121), we get a palindrome (241021222120142).

The spelling of 121021111000021 in words is "one hundred twenty-one trillion, twenty-one billion, one hundred eleven million, twenty-one", and thus it is an aban number.