31232231021 has 4 divisors (see below), whose sum is σ = 31232785500. Its totient is φ = 31231676544.

The previous prime is 31232230957. The next prime is 31232231059. The reversal of 31232231021 is 12013223213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7819864900 + 23412366121 = 88430^2 + 153011^2 .

It is a cyclic number.

It is not a de Polignac number, because 31232231021 - 2⁶ = 31232230957 is a prime.

It is a super-2 number, since 2×31232231021² (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 = 31232230984 and 31232231002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31232231321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181796 + ... + 309053.

It is an arithmetic number, because the mean of its divisors is an integer number (7808196375).

Almost surely, 2^31232231021 is an apocalyptic number.

It is an amenable number.

31232231021 is a deficient number, since it is larger than the sum of its proper divisors (554479).

31232231021 is an equidigital number, since it uses as much as digits as its factorization.

31232231021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554478.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 31232231021 its reverse (12013223213), we get a palindrome (43245454234).

It can be divided in two parts, 312322 and 31021, that added together give a palindrome (343343).

The spelling of 31232231021 in words is "thirty-one billion, two hundred thirty-two million, two hundred thirty-one thousand, twenty-one".