206563993 has 2 divisors, whose sum is σ = 206563994. Its totient is φ = 206563992.

The previous prime is 206563979. The next prime is 206563999. The reversal of 206563993 is 399365602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 116920969 + 89643024 = 10813^2 + 9468^2 .

It is a cyclic number.

It is not a de Polignac number, because 206563993 - 2²¹ = 204466841 is a prime.

It is not a weakly prime, because it can be changed into another prime (206563999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103281996 + 103281997.

It is an arithmetic number, because the mean of its divisors is an integer number (103281997).

Almost surely, 2^206563993 is an apocalyptic number.

It is an amenable number.

206563993 is a deficient number, since it is larger than the sum of its proper divisors (1).

206563993 is an equidigital number, since it uses as much as digits as its factorization.

206563993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 262440, while the sum is 43.

The square root of 206563993 is about 14372.3342919652. The cubic root of 206563993 is about 591.1325492915.

It can be divided in two parts, 20656 and 3993, that added together give a square (24649 = 157²).

The spelling of 206563993 in words is "two hundred six million, five hundred sixty-three thousand, nine hundred ninety-three".