205006921 has 4 divisors (see below), whose sum is σ = 234293632. Its totient is φ = 175720212.

The previous prime is 205006897. The next prime is 205006931. The reversal of 205006921 is 129600502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 205006921 - 2⁷ = 205006793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205006931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14643345 + ... + 14643358.

It is an arithmetic number, because the mean of its divisors is an integer number (58573408).

Almost surely, 2^205006921 is an apocalyptic number.

It is an amenable number.

205006921 is a deficient number, since it is larger than the sum of its proper divisors (29286711).

205006921 is an equidigital number, since it uses as much as digits as its factorization.

205006921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29286710.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 205006921 is about 14318.0627530403. The cubic root of 205006921 is about 589.6434894942.

The spelling of 205006921 in words is "two hundred five million, six thousand, nine hundred twenty-one".