21220101112121 has 8 divisors (see below), whose sum is σ = 21709409197824. Its totient is φ = 20736082843840.

The previous prime is 21220101112117. The next prime is 21220101112157. The reversal of 21220101112121 is 12121110102212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21220101112121 - 2² = 21220101112117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21220101112121.

It is not an unprimeable number, because it can be changed into a prime (21220101118121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1322446241 + ... + 1322462286.

It is an arithmetic number, because the mean of its divisors is an integer number (2713676149728).

Almost surely, 2^{21220101112121} is an apocalyptic number.

It is an amenable number.

21220101112121 is a deficient number, since it is larger than the sum of its proper divisors (489308085703).

21220101112121 is a wasteful number, since it uses less digits than its factorization.

21220101112121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2644908711.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21220101112121 its reverse (12121110102212), we get a palindrome (33341211214333).

The spelling of 21220101112121 in words is "twenty-one trillion, two hundred twenty billion, one hundred one million, one hundred twelve thousand, one hundred twenty-one".