206045681 has 2 divisors, whose sum is σ = 206045682. Its totient is φ = 206045680.

The previous prime is 206045663. The next prime is 206045683. The reversal of 206045681 is 186540602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198669025 + 7376656 = 14095^2 + 2716^2 .

It is a cyclic number.

It is not a de Polignac number, because 206045681 - 2²⁶ = 138936817 is a prime.

It is a super-2 number, since 2×206045681² = 84909645317507522, which contains 22 as substring.

Together with 206045683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (206045683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103022840 + 103022841.

It is an arithmetic number, because the mean of its divisors is an integer number (103022841).

Almost surely, 2^206045681 is an apocalyptic number.

It is an amenable number.

206045681 is a deficient number, since it is larger than the sum of its proper divisors (1).

206045681 is an equidigital number, since it uses as much as digits as its factorization.

206045681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 206045681 is about 14354.2913792357. The cubic root of 206045681 is about 590.6377103579.

The spelling of 206045681 in words is "two hundred six million, forty-five thousand, six hundred eighty-one".