31000020321 has 4 divisors (see below), whose sum is σ = 41333360432. Its totient is φ = 20666680212.

The previous prime is 31000020299. The next prime is 31000020397. The reversal of 31000020321 is 12302000013.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 31000020321 - 2⁶ = 31000020257 is a prime.

It is a super-2 number, since 2×31000020321² (a number of 22 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 = 31000020297 and 31000020306.

It is not an unprimeable number, because it can be changed into a prime (31000020221) 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, 5166670051 + ... + 5166670056.

It is an arithmetic number, because the mean of its divisors is an integer number (10333340108).

Almost surely, 2^31000020321 is an apocalyptic number.

It is an amenable number.

31000020321 is a deficient number, since it is larger than the sum of its proper divisors (10333340111).

31000020321 is a wasteful number, since it uses less digits than its factorization.

31000020321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10333340110.

The product of its (nonzero) digits is 36, while the sum is 12.

Adding to 31000020321 its reverse (12302000013), we get a palindrome (43302020334).

The spelling of 31000020321 in words is "thirty-one billion, twenty thousand, three hundred twenty-one".