204123721 has 8 divisors (see below), whose sum is σ = 212169600. Its totient is φ = 196145040.

The previous prime is 204123659. The next prime is 204123757. The reversal of 204123721 is 127321402.

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 204123721 - 2¹³ = 204115529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204123692 and 204123701.

It is not an unprimeable number, because it can be changed into a prime (204123221) 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, 10561 + ... + 22798.

It is an arithmetic number, because the mean of its divisors is an integer number (26521200).

Almost surely, 2^204123721 is an apocalyptic number.

It is an amenable number.

204123721 is a deficient number, since it is larger than the sum of its proper divisors (8045879).

204123721 is a wasteful number, since it uses less digits than its factorization.

204123721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33599.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 204123721 is about 14287.1873019150. The cubic root of 204123721 is about 588.7955136011.

The spelling of 204123721 in words is "two hundred four million, one hundred twenty-three thousand, seven hundred twenty-one".