31228389 has 16 divisors (see below), whose sum is σ = 47860800. Its totient is φ = 20100528.

The previous prime is 31228387. The next prime is 31228453. The reversal of 31228389 is 98382213.

It is a happy number.

It is not a de Polignac number, because 31228389 - 2¹ = 31228387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31228387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19159 + ... + 20724.

It is an arithmetic number, because the mean of its divisors is an integer number (2991300).

Almost surely, 2^31228389 is an apocalyptic number.

It is an amenable number.

31228389 is a deficient number, since it is larger than the sum of its proper divisors (16632411).

31228389 is a wasteful number, since it uses less digits than its factorization.

31228389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39921 (or 39915 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 31228389 is about 5588.2366628481. The cubic root of 31228389 is about 314.9076373196.

It can be divided in two parts, 3122 and 8389, that added together give a palindrome (11511).

The spelling of 31228389 in words is "thirty-one million, two hundred twenty-eight thousand, three hundred eighty-nine".