21313031121 has 48 divisors (see below), whose sum is σ = 35273556864. Its totient is φ = 12791395584.

The previous prime is 21313031119. The next prime is 21313031137. The reversal of 21313031121 is 12113031312.

21313031121 is a `hidden beast` number, since 21 + 313 + 0 + 311 + 21 = 666.

It is not a de Polignac number, because 21313031121 - 2¹ = 21313031119 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21313031094 and 21313031103.

It is not an unprimeable number, because it can be changed into a prime (21313031191) 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 47 ways as a sum of consecutive naturals, for example, 17146 + ... + 207171.

It is an arithmetic number, because the mean of its divisors is an integer number (734865768).

Almost surely, 2^21313031121 is an apocalyptic number.

It is an amenable number.

21313031121 is a deficient number, since it is larger than the sum of its proper divisors (13960525743).

21313031121 is a wasteful number, since it uses less digits than its factorization.

21313031121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224372 (or 224360 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21313031121 its reverse (12113031312), we get a palindrome (33426062433).

The spelling of 21313031121 in words is "twenty-one billion, three hundred thirteen million, thirty-one thousand, one hundred twenty-one".