205047421 has 16 divisors (see below), whose sum is σ = 220492800. Its totient is φ = 190003968.

The previous prime is 205047419. The next prime is 205047431. The reversal of 205047421 is 124740502.

It is not a de Polignac number, because 205047421 - 2¹ = 205047419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205047431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 442636 + ... + 443098.

It is an arithmetic number, because the mean of its divisors is an integer number (13780800).

Almost surely, 2^205047421 is an apocalyptic number.

It is an amenable number.

205047421 is a deficient number, since it is larger than the sum of its proper divisors (15445379).

205047421 is a wasteful number, since it uses less digits than its factorization.

205047421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 828.

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 205047421 is about 14319.4769806722. The cubic root of 205047421 is about 589.6823158076.

Adding to 205047421 its reverse (124740502), we get a palindrome (329787923).

The spelling of 205047421 in words is "two hundred five million, forty-seven thousand, four hundred twenty-one".