231217993 has 2 divisors, whose sum is σ = 231217994. Its totient is φ = 231217992.

The previous prime is 231217967. The next prime is 231218093. The reversal of 231217993 is 399712132.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154952704 + 76265289 = 12448^2 + 8733^2 .

It is a cyclic number.

It is not a de Polignac number, because 231217993 - 2¹³ = 231209801 is a prime.

It is not a weakly prime, because it can be changed into another prime (231217913) 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, 115608996 + 115608997.

It is an arithmetic number, because the mean of its divisors is an integer number (115608997).

Almost surely, 2^231217993 is an apocalyptic number.

It is an amenable number.

231217993 is a deficient number, since it is larger than the sum of its proper divisors (1).

231217993 is an equidigital number, since it uses as much as digits as its factorization.

231217993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20412, while the sum is 37.

The square root of 231217993 is about 15205.8539056509. The cubic root of 231217993 is about 613.7721933563.

The spelling of 231217993 in words is "two hundred thirty-one million, two hundred seventeen thousand, nine hundred ninety-three".