205131551 has 2 divisors, whose sum is σ = 205131552. Its totient is φ = 205131550.

The previous prime is 205131541. The next prime is 205131601. The reversal of 205131551 is 155131502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205131551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205131541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102565775 + 102565776.

It is an arithmetic number, because the mean of its divisors is an integer number (102565776).

Almost surely, 2^205131551 is an apocalyptic number.

205131551 is a deficient number, since it is larger than the sum of its proper divisors (1).

205131551 is an equidigital number, since it uses as much as digits as its factorization.

205131551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 205131551 is about 14322.4142867046. The cubic root of 205131551 is about 589.7629527478.

The spelling of 205131551 in words is "two hundred five million, one hundred thirty-one thousand, five hundred fifty-one".