31228081 has 2 divisors, whose sum is σ = 31228082. Its totient is φ = 31228080.

The previous prime is 31228073. The next prime is 31228117. The reversal of 31228081 is 18082213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31080625 + 147456 = 5575^2 + 384^2 .

It is an emirp because it is prime and its reverse (18082213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31228081 - 2³ = 31228073 is a prime.

It is a super-2 number, since 2×31228081² = 1950386085885122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31228061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15614040 + 15614041.

It is an arithmetic number, because the mean of its divisors is an integer number (15614041).

Almost surely, 2^31228081 is an apocalyptic number.

It is an amenable number.

31228081 is a deficient number, since it is larger than the sum of its proper divisors (1).

31228081 is an equidigital number, since it uses as much as digits as its factorization.

31228081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 31228081 is about 5588.2091048922. The cubic root of 31228081 is about 314.9066020237.

The spelling of 31228081 in words is "thirty-one million, two hundred twenty-eight thousand, eighty-one".