212121022121021 has 24 divisors (see below), whose sum is σ = 241133149716480. Its totient is φ = 185468323718304.

The previous prime is 212121022120981. The next prime is 212121022121033. The reversal of 212121022121021 is 120121220121212.

It is a de Polignac number, because none of the positive numbers 2^k-212121022121021 is a prime.

It is a super-3 number, since 3×212121022121021³ (a number of 44 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212121022120984 and 212121022121002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212121022121821) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25150160 + ... + 32508038.

It is an arithmetic number, because the mean of its divisors is an integer number (10047214571520).

Almost surely, 2^{212121022121021} is an apocalyptic number.

It is an amenable number.

212121022121021 is a deficient number, since it is larger than the sum of its proper divisors (29012127595459).

212121022121021 is a wasteful number, since it uses less digits than its factorization.

212121022121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7364073 (or 7364054 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 212121022121021 its reverse (120121220121212), we get a palindrome (332242242242233).

The spelling of 212121022121021 in words is "two hundred twelve trillion, one hundred twenty-one billion, twenty-two million, one hundred twenty-one thousand, twenty-one".