21313203031 has 4 divisors (see below), whose sum is σ = 21662599864. Its totient is φ = 20963806200.

The previous prime is 21313203029. The next prime is 21313203047. The reversal of 21313203031 is 13030231312.

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

It is a cyclic number.

It is not a de Polignac number, because 21313203031 - 2¹ = 21313203029 is a prime.

It is a super-2 number, since 2×21313203031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313203001) 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, 174698325 + ... + 174698446.

It is an arithmetic number, because the mean of its divisors is an integer number (5415649966).

Almost surely, 2^21313203031 is an apocalyptic number.

21313203031 is a deficient number, since it is larger than the sum of its proper divisors (349396833).

21313203031 is an equidigital number, since it uses as much as digits as its factorization.

21313203031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349396832.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 21313203031 its reverse (13030231312), we get a palindrome (34343434343).

The spelling of 21313203031 in words is "twenty-one billion, three hundred thirteen million, two hundred three thousand, thirty-one".