315551993 has 2 divisors, whose sum is σ = 315551994. Its totient is φ = 315551992.

The previous prime is 315551953. The next prime is 315552071. The reversal of 315551993 is 399155513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 314956009 + 595984 = 17747^2 + 772^2 .

It is a cyclic number.

It is not a de Polignac number, because 315551993 - 2¹⁰ = 315550969 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 315551993.

It is not a weakly prime, because it can be changed into another prime (315551923) 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, 157775996 + 157775997.

It is an arithmetic number, because the mean of its divisors is an integer number (157775997).

Almost surely, 2^315551993 is an apocalyptic number.

It is an amenable number.

315551993 is a deficient number, since it is larger than the sum of its proper divisors (1).

315551993 is an equidigital number, since it uses as much as digits as its factorization.

315551993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 91125, while the sum is 41.

The square root of 315551993 is about 17763.7831837703. The cubic root of 315551993 is about 680.8064200091.

The spelling of 315551993 in words is "three hundred fifteen million, five hundred fifty-one thousand, nine hundred ninety-three".