31000022321 has 4 divisors (see below), whose sum is σ = 31659597312. Its totient is φ = 30340447332.

The previous prime is 31000022303. The next prime is 31000022329. The reversal of 31000022321 is 12322000013.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31000022321 is a prime.

It is a super-2 number, since 2×31000022321² (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 = 31000022296 and 31000022305.

It is not an unprimeable number, because it can be changed into a prime (31000022329) 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, 329787425 + ... + 329787518.

It is an arithmetic number, because the mean of its divisors is an integer number (7914899328).

Almost surely, 2^31000022321 is an apocalyptic number.

It is an amenable number.

31000022321 is a deficient number, since it is larger than the sum of its proper divisors (659574991).

31000022321 is an equidigital number, since it uses as much as digits as its factorization.

31000022321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659574990.

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

Adding to 31000022321 its reverse (12322000013), we get a palindrome (43322022334).

The spelling of 31000022321 in words is "thirty-one billion, twenty-two thousand, three hundred twenty-one".