21010022121 has 32 divisors (see below), whose sum is σ = 30887473536. Its totient is φ = 12597120000.

The previous prime is 21010022063. The next prime is 21010022123. The reversal of 21010022121 is 12122001012.

It is not a de Polignac number, because 21010022121 - 2¹⁸ = 21009759977 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21010022097 and 21010022106.

It is not an unprimeable number, because it can be changed into a prime (21010022123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7201155 + ... + 7204071.

It is an arithmetic number, because the mean of its divisors is an integer number (965233548).

Almost surely, 2^21010022121 is an apocalyptic number.

It is an amenable number.

21010022121 is a deficient number, since it is larger than the sum of its proper divisors (9877451415).

21010022121 is a wasteful number, since it uses less digits than its factorization.

21010022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5193.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21010022121 its reverse (12122001012), we get a palindrome (33132023133).

It can be divided in two parts, 210100 and 22121, that added together give a triangular number (232221 = T₆₈₁).

The spelling of 21010022121 in words is "twenty-one billion, ten million, twenty-two thousand, one hundred twenty-one".