21031311131220 has 96 divisors (see below), whose sum is σ = 63428000614272. Its totient is φ = 5176080281088.

The previous prime is 21031311131189. The next prime is 21031311131267. The reversal of 21031311131220 is 2213111313012.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2482594 + ... + 6944486.

It is an arithmetic number, because the mean of its divisors is an integer number (660708339732).

Almost surely, 2^{21031311131220} is an apocalyptic number.

21031311131220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21031311131220 is an abundant number, since it is smaller than the sum of its proper divisors (42396689483052).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21031311131220 is a wasteful number, since it uses less digits than its factorization.

21031311131220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4467961 (or 4467959 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

Adding to 21031311131220 its reverse (2213111313012), we get a palindrome (23244422444232).

The spelling of 21031311131220 in words is "twenty-one trillion, thirty-one billion, three hundred eleven million, one hundred thirty-one thousand, two hundred twenty".