21022220121 has 8 divisors (see below), whose sum is σ = 32033859264. Its totient is φ = 12012697200.

The previous prime is 21022220083. The next prime is 21022220159. The reversal of 21022220121 is 12102222012.

It is an interprime number because it is at equal distance from previous prime (21022220083) and next prime (21022220159).

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

It is not a de Polignac number, because 21022220121 - 2¹⁵ = 21022187353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21022220121.

It is not an unprimeable number, because it can be changed into a prime (21022220171) 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, 500529030 + ... + 500529071.

It is an arithmetic number, because the mean of its divisors is an integer number (4004232408).

Almost surely, 2^21022220121 is an apocalyptic number.

21022220121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21022220121 is a deficient number, since it is larger than the sum of its proper divisors (11011639143).

21022220121 is a wasteful number, since it uses less digits than its factorization.

21022220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001058111.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21022220121 its reverse (12102222012), we get a palindrome (33124442133).

The spelling of 21022220121 in words is "twenty-one billion, twenty-two million, two hundred twenty thousand, one hundred twenty-one".