121221212121021 has 32 divisors (see below), whose sum is σ = 165838878317952. Its totient is φ = 78715251440640.

The previous prime is 121221212120927. The next prime is 121221212121083. The reversal of 121221212121021 is 120121212122121.

It is not a de Polignac number, because 121221212121021 - 2⁹ = 121221212120509 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221212121221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1467296911 + ... + 1467379523.

It is an arithmetic number, because the mean of its divisors is an integer number (5182464947436).

Almost surely, 2^{121221212121021} is an apocalyptic number.

It is an amenable number.

121221212121021 is a deficient number, since it is larger than the sum of its proper divisors (44617666196931).

121221212121021 is a wasteful number, since it uses less digits than its factorization.

121221212121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101853.

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 121221212121021 its reverse (120121212122121), we get a palindrome (241342424243142).

The spelling of 121221212121021 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred twenty-one thousand, twenty-one".