209400031 has 2 divisors, whose sum is σ = 209400032. Its totient is φ = 209400030.

The previous prime is 209400029. The next prime is 209400041. The reversal of 209400031 is 130004902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209400031 - 2¹ = 209400029 is a prime.

It is a super-2 number, since 2×209400031² = 87696745965601922, which contains 22 as substring.

Together with 209400029, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 209399981 and 209400008.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209400041) 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, 104700015 + 104700016.

It is an arithmetic number, because the mean of its divisors is an integer number (104700016).

Almost surely, 2^209400031 is an apocalyptic number.

209400031 is a deficient number, since it is larger than the sum of its proper divisors (1).

209400031 is an equidigital number, since it uses as much as digits as its factorization.

209400031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 209400031 is about 14470.6610422606. The cubic root of 209400031 is about 593.8255967864.

Adding to 209400031 its reverse (130004902), we get a palindrome (339404933).

The spelling of 209400031 in words is "two hundred nine million, four hundred thousand, thirty-one".