205355021 has 8 divisors (see below), whose sum is σ = 216406080. Its totient is φ = 194328288.

The previous prime is 205355009. The next prime is 205355023. The reversal of 205355021 is 120553502.

205355021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 205355021 - 2⁶ = 205354957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205355023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12785 + ... + 23961.

It is an arithmetic number, because the mean of its divisors is an integer number (27050760).

Almost surely, 2^205355021 is an apocalyptic number.

It is an amenable number.

205355021 is a deficient number, since it is larger than the sum of its proper divisors (11051059).

205355021 is a wasteful number, since it uses less digits than its factorization.

205355021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12163.

The product of its (nonzero) digits is 1500, while the sum is 23.

The square root of 205355021 is about 14330.2135713324. The cubic root of 205355021 is about 589.9770373137.

The spelling of 205355021 in words is "two hundred five million, three hundred fifty-five thousand, twenty-one".