31132321 has 16 divisors (see below), whose sum is σ = 36167040. Its totient is φ = 26484480.

The previous prime is 31132303. The next prime is 31132327. The reversal of 31132321 is 12323113.

It is not a de Polignac number, because 31132321 - 2⁷ = 31132193 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31132295 and 31132304.

It is not an unprimeable number, because it can be changed into a prime (31132327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42460 + ... + 43186.

It is an arithmetic number, because the mean of its divisors is an integer number (2260440).

Almost surely, 2^31132321 is an apocalyptic number.

It is an amenable number.

31132321 is a deficient number, since it is larger than the sum of its proper divisors (5034719).

31132321 is a wasteful number, since it uses less digits than its factorization.

31132321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984.

The product of its digits is 108, while the sum is 16.

The square root of 31132321 is about 5579.6344862365. The cubic root of 31132321 is about 314.5843884745.

Adding to 31132321 its reverse (12323113), we get a palindrome (43455434).

The spelling of 31132321 in words is "thirty-one million, one hundred thirty-two thousand, three hundred twenty-one".