121212210021 has 32 divisors (see below), whose sum is σ = 193508302848. Its totient is φ = 66029325120.

The previous prime is 121212210013. The next prime is 121212210023. The reversal of 121212210021 is 120012212121.

It is not a de Polignac number, because 121212210021 - 2³ = 121212210013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212210023) 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, 1345890 + ... + 1433123.

It is an arithmetic number, because the mean of its divisors is an integer number (6047134464).

Almost surely, 2^121212210021 is an apocalyptic number.

It is an amenable number.

121212210021 is a deficient number, since it is larger than the sum of its proper divisors (72296092827).

121212210021 is a wasteful number, since it uses less digits than its factorization.

121212210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2779121.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 121212210021 its reverse (120012212121), we get a palindrome (241224422142).

The spelling of 121212210021 in words is "one hundred twenty-one billion, two hundred twelve million, two hundred ten thousand, twenty-one".