31229999 has 2 divisors, whose sum is σ = 31230000. Its totient is φ = 31229998.

The previous prime is 31229993. The next prime is 31230029. The reversal of 31229999 is 99992213.

It is a weak prime.

It is an emirp because it is prime and its reverse (99992213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31229999 - 2¹² = 31225903 is a prime.

31229999 is a modest number, since divided by 9999 gives 3122 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31229993) 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 as a sum of consecutive naturals, namely, 15614999 + 15615000.

It is an arithmetic number, because the mean of its divisors is an integer number (15615000).

Almost surely, 2^31229999 is an apocalyptic number.

31229999 is a deficient number, since it is larger than the sum of its proper divisors (1).

31229999 is an equidigital number, since it uses as much as digits as its factorization.

31229999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 78732, while the sum is 44.

The square root of 31229999 is about 5588.3807135878. The cubic root of 31229999 is about 314.9130489830.

The spelling of 31229999 in words is "thirty-one million, two hundred twenty-nine thousand, nine hundred ninety-nine".