21000031230031 has 12 divisors (see below), whose sum is σ = 24703086501360. Its totient is φ = 17797779273120.

The previous prime is 21000031229939. The next prime is 21000031230049. The reversal of 21000031230031 is 13003213000012.

It is not a de Polignac number, because 21000031230031 - 2¹⁹ = 21000030705743 is a prime.

It is a super-2 number, since 2×21000031230031² (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 = 21000031229987 and 21000031230014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000031230131) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2407703875 + ... + 2407712596.

It is an arithmetic number, because the mean of its divisors is an integer number (2058590541780).

Almost surely, 2^{21000031230031} is an apocalyptic number.

21000031230031 is a deficient number, since it is larger than the sum of its proper divisors (3703055271329).

21000031230031 is an equidigital number, since it uses as much as digits as its factorization.

21000031230031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4815416574 (or 4815416567 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21000031230031 its reverse (13003213000012), we get a palindrome (34003244230043).

The spelling of 21000031230031 in words is "twenty-one trillion, thirty-one million, two hundred thirty thousand, thirty-one".