205215251 has 2 divisors, whose sum is σ = 205215252. Its totient is φ = 205215250.

The previous prime is 205215229. The next prime is 205215277. The reversal of 205215251 is 152512502.

205215251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205215251 - 2²⁶ = 138106387 is a prime.

It is a super-2 number, since 2×205215251² = 84226598485986002, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (205215151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102607625 + 102607626.

It is an arithmetic number, because the mean of its divisors is an integer number (102607626).

Almost surely, 2^205215251 is an apocalyptic number.

205215251 is a deficient number, since it is larger than the sum of its proper divisors (1).

205215251 is an equidigital number, since it uses as much as digits as its factorization.

205215251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 205215251 is about 14325.3359820983. The cubic root of 205215251 is about 589.8431556656.

Adding to 205215251 its reverse (152512502), we get a palindrome (357727753).

The spelling of 205215251 in words is "two hundred five million, two hundred fifteen thousand, two hundred fifty-one".