21022021121 has 16 divisors (see below), whose sum is σ = 21722964480. Its totient is φ = 20328459840.

The previous prime is 21022021067. The next prime is 21022021157. The reversal of 21022021121 is 12112022012.

It is a cyclic number.

It is not a de Polignac number, because 21022021121 - 2¹⁴ = 21022004737 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21022021096 and 21022021105.

It is not an unprimeable number, because it can be changed into a prime (21022021921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4414940 + ... + 4419698.

It is an arithmetic number, because the mean of its divisors is an integer number (1357685280).

Almost surely, 2^21022021121 is an apocalyptic number.

It is an amenable number.

21022021121 is a deficient number, since it is larger than the sum of its proper divisors (700943359).

21022021121 is a wasteful number, since it uses less digits than its factorization.

21022021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5504.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21022021121 its reverse (12112022012), we get a palindrome (33134043133).

The spelling of 21022021121 in words is "twenty-one billion, twenty-two million, twenty-one thousand, one hundred twenty-one".