21313021033231 has 4 divisors (see below), whose sum is σ = 21456061443000. Its totient is φ = 21169980623464.

The previous prime is 21313021033219. The next prime is 21313021033277. The reversal of 21313021033231 is 13233012031312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21313021033231 is a prime.

It is a super-2 number, since 2×21313021033231² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21313021033196 and 21313021033205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313021033211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71520204661 + ... + 71520204958.

It is an arithmetic number, because the mean of its divisors is an integer number (5364015360750).

Almost surely, 2^{21313021033231} is an apocalyptic number.

21313021033231 is a deficient number, since it is larger than the sum of its proper divisors (143040409769).

21313021033231 is a wasteful number, since it uses less digits than its factorization.

21313021033231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143040409768.

The product of its (nonzero) digits is 1944, while the sum is 25.

Adding to 21313021033231 its reverse (13233012031312), we get a palindrome (34546033064543).

The spelling of 21313021033231 in words is "twenty-one trillion, three hundred thirteen billion, twenty-one million, thirty-three thousand, two hundred thirty-one".