215931193 has 2 divisors, whose sum is σ = 215931194. Its totient is φ = 215931192.

The previous prime is 215931137. The next prime is 215931203. The reversal of 215931193 is 391139512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122943744 + 92987449 = 11088^2 + 9643^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215931193 is a prime.

It is a super-2 number, since 2×215931193² = 93252560220806498, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (215931293) 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, 107965596 + 107965597.

It is an arithmetic number, because the mean of its divisors is an integer number (107965597).

Almost surely, 2^215931193 is an apocalyptic number.

It is an amenable number.

215931193 is a deficient number, since it is larger than the sum of its proper divisors (1).

215931193 is an equidigital number, since it uses as much as digits as its factorization.

215931193 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7290, while the sum is 34.

The square root of 215931193 is about 14694.5974085716. The cubic root of 215931193 is about 599.9362830486.

The spelling of 215931193 in words is "two hundred fifteen million, nine hundred thirty-one thousand, one hundred ninety-three".