205140921 has 8 divisors (see below), whose sum is σ = 289610784. Its totient is φ = 128715840.

The previous prime is 205140893. The next prime is 205140931. The reversal of 205140921 is 129041502.

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

It is not a de Polignac number, because 205140921 - 2²⁵ = 171586489 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205140891 and 205140900.

It is not an unprimeable number, because it can be changed into a prime (205140931) 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, 2011135 + ... + 2011236.

It is an arithmetic number, because the mean of its divisors is an integer number (36201348).

Almost surely, 2^205140921 is an apocalyptic number.

It is an amenable number.

205140921 is a deficient number, since it is larger than the sum of its proper divisors (84469863).

205140921 is a wasteful number, since it uses less digits than its factorization.

205140921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4022391.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 205140921 is about 14322.7413926245. The cubic root of 205140921 is about 589.7719323428.

The spelling of 205140921 in words is "two hundred five million, one hundred forty thousand, nine hundred twenty-one".