206510516591 has 2 divisors, whose sum is σ = 206510516592. Its totient is φ = 206510516590.

The previous prime is 206510516501. The next prime is 206510516617. The reversal of 206510516591 is 195615015602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 206510516591 - 2²² = 206506322287 is a prime.

It is a super-2 number, since 2×206510516591² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206510516501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103255258295 + 103255258296.

It is an arithmetic number, because the mean of its divisors is an integer number (103255258296).

Almost surely, 2^206510516591 is an apocalyptic number.

206510516591 is a deficient number, since it is larger than the sum of its proper divisors (1).

206510516591 is an equidigital number, since it uses as much as digits as its factorization.

206510516591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81000, while the sum is 41.

The spelling of 206510516591 in words is "two hundred six billion, five hundred ten million, five hundred sixteen thousand, five hundred ninety-one".