21112120221 has 8 divisors (see below), whose sum is σ = 28312208160. Its totient is φ = 13993389552.

The previous prime is 21112120219. The next prime is 21112120243. The reversal of 21112120221 is 12202121112.

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

It is not a de Polignac number, because 21112120221 - 2¹ = 21112120219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21112120221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112120121) 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, 20338711 + ... + 20339748.

It is an arithmetic number, because the mean of its divisors is an integer number (3539026020).

Almost surely, 2^21112120221 is an apocalyptic number.

It is an amenable number.

21112120221 is a deficient number, since it is larger than the sum of its proper divisors (7200087939).

21112120221 is a wasteful number, since it uses less digits than its factorization.

21112120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40678635.

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

Adding to 21112120221 its reverse (12202121112), we get a palindrome (33314241333).

The spelling of 21112120221 in words is "twenty-one billion, one hundred twelve million, one hundred twenty thousand, two hundred twenty-one".