205215401 has 2 divisors, whose sum is σ = 205215402. Its totient is φ = 205215400.

The previous prime is 205215389. The next prime is 205215403. The reversal of 205215401 is 104512502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 103225600 + 101989801 = 10160^2 + 10099^2 .

It is a cyclic number.

It is not a de Polignac number, because 205215401 - 2¹⁰ = 205214377 is a prime.

It is a super-2 number, since 2×205215401² = 84226721615181602, which contains 22 as substring.

Together with 205215403, 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 (205215403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102607700 + 102607701.

It is an arithmetic number, because the mean of its divisors is an integer number (102607701).

Almost surely, 2^205215401 is an apocalyptic number.

It is an amenable number.

205215401 is a deficient number, since it is larger than the sum of its proper divisors (1).

205215401 is an equidigital number, since it uses as much as digits as its factorization.

205215401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 205215401 is about 14325.3412175766. The cubic root of 205215401 is about 589.8432993789.

Adding to 205215401 its reverse (104512502), we get a palindrome (309727903).

The spelling of 205215401 in words is "two hundred five million, two hundred fifteen thousand, four hundred one".