205401961 has 2 divisors, whose sum is σ = 205401962. Its totient is φ = 205401960.

The previous prime is 205401953. The next prime is 205401971. The reversal of 205401961 is 169104502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184416400 + 20985561 = 13580^2 + 4581^2 .

It is a cyclic number.

It is not a de Polignac number, because 205401961 - 2³ = 205401953 is a prime.

It is not a weakly prime, because it can be changed into another prime (205401901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102700980 + 102700981.

It is an arithmetic number, because the mean of its divisors is an integer number (102700981).

Almost surely, 2^205401961 is an apocalyptic number.

It is an amenable number.

205401961 is a deficient number, since it is larger than the sum of its proper divisors (1).

205401961 is an equidigital number, since it uses as much as digits as its factorization.

205401961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 205401961 is about 14331.8512760913. The cubic root of 205401961 is about 590.0219861576.

The spelling of 205401961 in words is "two hundred five million, four hundred one thousand, nine hundred sixty-one".