31431229 has 2 divisors, whose sum is σ = 31431230. Its totient is φ = 31431228.

The previous prime is 31431227. The next prime is 31431233. The reversal of 31431229 is 92213413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18507204 + 12924025 = 4302^2 + 3595^2 .

It is an emirp because it is prime and its reverse (92213413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31431229 - 2¹ = 31431227 is a prime.

Together with 31431227, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31431221) 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 as a sum of consecutive naturals, namely, 15715614 + 15715615.

It is an arithmetic number, because the mean of its divisors is an integer number (15715615).

Almost surely, 2^31431229 is an apocalyptic number.

It is an amenable number.

31431229 is a deficient number, since it is larger than the sum of its proper divisors (1).

31431229 is an equidigital number, since it uses as much as digits as its factorization.

31431229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 25.

The square root of 31431229 is about 5606.3561249710. The cubic root of 31431229 is about 315.5879804832.

The spelling of 31431229 in words is "thirty-one million, four hundred thirty-one thousand, two hundred twenty-nine".