21012122022221 has 8 divisors (see below), whose sum is σ = 22922686113600. Its totient is φ = 19101619794240.

The previous prime is 21012122022217. The next prime is 21012122022247. The reversal of 21012122022221 is 12222022121012.

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 21012122022221 - 2² = 21012122022217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012122022193 and 21012122022202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012122022211) 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, 14754236 + ... + 16115573.

It is an arithmetic number, because the mean of its divisors is an integer number (2865335764200).

Almost surely, 2^{21012122022221} is an apocalyptic number.

It is an amenable number.

21012122022221 is a deficient number, since it is larger than the sum of its proper divisors (1910564091379).

21012122022221 is a wasteful number, since it uses less digits than its factorization.

21012122022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30931699.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21012122022221 its reverse (12222022121012), we get a palindrome (33234144143233).

The spelling of 21012122022221 in words is "twenty-one trillion, twelve billion, one hundred twenty-two million, twenty-two thousand, two hundred twenty-one".