31381233 has 16 divisors (see below), whose sum is σ = 45224256. Its totient is φ = 19241280.

The previous prime is 31381213. The next prime is 31381241. The reversal of 31381233 is 33218313.

It is not a de Polignac number, because 31381233 - 2⁶ = 31381169 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31381213) 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 15 ways as a sum of consecutive naturals, for example, 10663 + ... + 13283.

It is an arithmetic number, because the mean of its divisors is an integer number (2826516).

Almost surely, 2^31381233 is an apocalyptic number.

It is an amenable number.

31381233 is a deficient number, since it is larger than the sum of its proper divisors (13843023).

31381233 is a wasteful number, since it uses less digits than its factorization.

31381233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2944.

The product of its digits is 1296, while the sum is 24.

The square root of 31381233 is about 5601.8954827808. The cubic root of 31381233 is about 315.4205619593.

Adding to 31381233 its reverse (33218313), we get a palindrome (64599546).

It can be divided in two parts, 3138 and 1233, that added together give a triangular number (4371 = T₉₃).

The spelling of 31381233 in words is "thirty-one million, three hundred eighty-one thousand, two hundred thirty-three".