21000322031 has 4 divisors (see below), whose sum is σ = 22615731432. Its totient is φ = 19384912632.

The previous prime is 21000321997. The next prime is 21000322039. The reversal of 21000322031 is 13022300012.

It is a happy number.

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 21000322031 - 2¹⁴ = 21000305647 is a prime.

It is a super-2 number, since 2×21000322031² (a number of 21 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 = 21000321997 and 21000322015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000322039) 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, 807704681 + ... + 807704706.

It is an arithmetic number, because the mean of its divisors is an integer number (5653932858).

Almost surely, 2^21000322031 is an apocalyptic number.

21000322031 is a deficient number, since it is larger than the sum of its proper divisors (1615409401).

21000322031 is a wasteful number, since it uses less digits than its factorization.

21000322031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615409400.

The product of its (nonzero) digits is 72, while the sum is 14.

Adding to 21000322031 its reverse (13022300012), we get a palindrome (34022622043).

The spelling of 21000322031 in words is "twenty-one billion, three hundred twenty-two thousand, thirty-one".