204750021 has 8 divisors (see below), whose sum is σ = 312000064. Its totient is φ = 117000000.

The previous prime is 204750019. The next prime is 204750031. The reversal of 204750021 is 120057402.

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

It is not a de Polignac number, because 204750021 - 2¹ = 204750019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 9750001 = 204750021 / (2 + 0 + 4 + 7 + 5 + 0 + 0 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 204750021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204750031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4874980 + ... + 4875021.

It is an arithmetic number, because the mean of its divisors is an integer number (39000008).

Almost surely, 2^204750021 is an apocalyptic number.

204750021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

204750021 is a deficient number, since it is larger than the sum of its proper divisors (107250043).

204750021 is an equidigital number, since it uses as much as digits as its factorization.

204750021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9750011.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 204750021 is about 14309.0887550536. The cubic root of 204750021 is about 589.3970868684.

The spelling of 204750021 in words is "two hundred four million, seven hundred fifty thousand, twenty-one".