205697651 has 2 divisors, whose sum is σ = 205697652. Its totient is φ = 205697650.

The previous prime is 205697587. The next prime is 205697669. The reversal of 205697651 is 156796502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205697651 - 2⁶ = 205697587 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205697599 and 205697608.

It is not a weakly prime, because it can be changed into another prime (205697351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102848825 + 102848826.

It is an arithmetic number, because the mean of its divisors is an integer number (102848826).

Almost surely, 2^205697651 is an apocalyptic number.

205697651 is a deficient number, since it is larger than the sum of its proper divisors (1).

205697651 is an equidigital number, since it uses as much as digits as its factorization.

205697651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 113400, while the sum is 41.

The square root of 205697651 is about 14342.1634002685. The cubic root of 205697651 is about 590.3049759106.

The spelling of 205697651 in words is "two hundred five million, six hundred ninety-seven thousand, six hundred fifty-one".