205506397 has 2 divisors, whose sum is σ = 205506398. Its totient is φ = 205506396.

The previous prime is 205506341. The next prime is 205506437. The reversal of 205506397 is 793605502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159415876 + 46090521 = 12626^2 + 6789^2 .

It is a cyclic number.

It is not a de Polignac number, because 205506397 - 2⁷ = 205506269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205506317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102753198 + 102753199.

It is an arithmetic number, because the mean of its divisors is an integer number (102753199).

Almost surely, 2^205506397 is an apocalyptic number.

It is an amenable number.

205506397 is a deficient number, since it is larger than the sum of its proper divisors (1).

205506397 is an equidigital number, since it uses as much as digits as its factorization.

205506397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56700, while the sum is 37.

The square root of 205506397 is about 14335.4943060921. The cubic root of 205506397 is about 590.1219675070.

The spelling of 205506397 in words is "two hundred five million, five hundred six thousand, three hundred ninety-seven".