205402081 has 2 divisors, whose sum is σ = 205402082. Its totient is φ = 205402080.

The previous prime is 205402061. The next prime is 205402117. The reversal of 205402081 is 180204502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164249856 + 41152225 = 12816^2 + 6415^2 .

It is a cyclic number.

It is not a de Polignac number, because 205402081 - 2⁵ = 205402049 is a prime.

It is a super-2 number, since 2×205402081² = 84380029758261122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (205402031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102701040 + 102701041.

It is an arithmetic number, because the mean of its divisors is an integer number (102701041).

Almost surely, 2^205402081 is an apocalyptic number.

It is an amenable number.

205402081 is a deficient number, since it is larger than the sum of its proper divisors (1).

205402081 is an equidigital number, since it uses as much as digits as its factorization.

205402081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 205402081 is about 14331.8554625701. The cubic root of 205402081 is about 590.0221010585.

Adding to 205402081 its reverse (180204502), we get a palindrome (385606583).

The spelling of 205402081 in words is "two hundred five million, four hundred two thousand, eighty-one".