31323133021 has 2 divisors, whose sum is σ = 31323133022. Its totient is φ = 31323133020.

The previous prime is 31323133007. The next prime is 31323133043. The reversal of 31323133021 is 12033132313.

It is an a-pointer prime, because the next prime (31323133043) can be obtained adding 31323133021 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28717030521 + 2606102500 = 169461^2 + 51050^2 .

It is a cyclic number.

It is not a de Polignac number, because 31323133021 - 2⁵ = 31323132989 is a prime.

It is a super-2 number, since 2×31323133021² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31323132983 and 31323133001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31323133921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15661566510 + 15661566511.

It is an arithmetic number, because the mean of its divisors is an integer number (15661566511).

Almost surely, 2^31323133021 is an apocalyptic number.

It is an amenable number.

31323133021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31323133021 is an equidigital number, since it uses as much as digits as its factorization.

31323133021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 22.

Adding to 31323133021 its reverse (12033132313), we get a palindrome (43356265334).

The spelling of 31323133021 in words is "thirty-one billion, three hundred twenty-three million, one hundred thirty-three thousand, twenty-one".