21210231023121 has 32 divisors (see below), whose sum is σ = 34548160002048. Its totient is φ = 11310409503360.

The previous prime is 21210231023087. The next prime is 21210231023141. The reversal of 21210231023121 is 12132013201212.

It is not a de Polignac number, because 21210231023121 - 2¹⁷ = 21210230892049 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21210231023141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 535510951 + ... + 535550556.

It is an arithmetic number, because the mean of its divisors is an integer number (1079630000064).

Almost surely, 2^{21210231023121} is an apocalyptic number.

21210231023121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21210231023121 is a deficient number, since it is larger than the sum of its proper divisors (13337928978927).

21210231023121 is a wasteful number, since it uses less digits than its factorization.

21210231023121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1071061581.

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 21210231023121 its reverse (12132013201212), we get a palindrome (33342244224333).

The spelling of 21210231023121 in words is "twenty-one trillion, two hundred ten billion, two hundred thirty-one million, twenty-three thousand, one hundred twenty-one".