31172243 has 2 divisors, whose sum is σ = 31172244. Its totient is φ = 31172242.

The previous prime is 31172209. The next prime is 31172263. The reversal of 31172243 is 34227113.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31172243 - 2¹² = 31168147 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (31172263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15586121 + 15586122.

It is an arithmetic number, because the mean of its divisors is an integer number (15586122).

Almost surely, 2^31172243 is an apocalyptic number.

31172243 is a deficient number, since it is larger than the sum of its proper divisors (1).

31172243 is an equidigital number, since it uses as much as digits as its factorization.

31172243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 23.

The square root of 31172243 is about 5583.2108145761. The cubic root of 31172243 is about 314.7187983437.

Adding to 31172243 its reverse (34227113), we get a palindrome (65399356).

The spelling of 31172243 in words is "thirty-one million, one hundred seventy-two thousand, two hundred forty-three".