21023131222121 has 12 divisors (see below), whose sum is σ = 25116438075588. Its totient is φ = 17532804415392.

The previous prime is 21023131222117. The next prime is 21023131222127. The reversal of 21023131222121 is 12122213132012.

It can be written as a sum of positive squares in 2 ways, for example, as 9779254752400 + 11243876469721 = 3127180^2 + 3353189^2 .

It is not a de Polignac number, because 21023131222121 - 2² = 21023131222117 is a prime.

It is a super-2 number, since 2×21023131222121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21023131222127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5797883246 + ... + 5797886871.

It is an arithmetic number, because the mean of its divisors is an integer number (2093036506299).

Almost surely, 2^{21023131222121} is an apocalyptic number.

It is an amenable number.

21023131222121 is a deficient number, since it is larger than the sum of its proper divisors (4093306853467).

21023131222121 is a wasteful number, since it uses less digits than its factorization.

21023131222121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11595770168 (or 11595770161 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

Adding to 21023131222121 its reverse (12122213132012), we get a palindrome (33145344354133).

The spelling of 21023131222121 in words is "twenty-one trillion, twenty-three billion, one hundred thirty-one million, two hundred twenty-two thousand, one hundred twenty-one".