121121111012021 has 4 divisors (see below), whose sum is σ = 125028243625344. Its totient is φ = 117213978398700.

The previous prime is 121121111012009. The next prime is 121121111012023. The reversal of 121121111012021 is 120210111121121.

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-121121111012021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121121111012023) 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, 1953566306615 + ... + 1953566306676.

It is an arithmetic number, because the mean of its divisors is an integer number (31257060906336).

Almost surely, 2^{121121111012021} is an apocalyptic number.

It is an amenable number.

121121111012021 is a deficient number, since it is larger than the sum of its proper divisors (3907132613323).

121121111012021 is an equidigital number, since it uses as much as digits as its factorization.

121121111012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3907132613322.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 121121111012021 its reverse (120210111121121), we get a palindrome (241331222133142).

The spelling of 121121111012021 in words is "one hundred twenty-one trillion, one hundred twenty-one billion, one hundred eleven million, twelve thousand, twenty-one".