204720817 has 16 divisors (see below), whose sum is σ = 249391872. Its totient is φ = 164044800.

The previous prime is 204720811. The next prime is 204720823. The reversal of 204720817 is 718027402.

204720817 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (204720811) and next prime (204720823).

It is a cyclic number.

It is not a de Polignac number, because 204720817 - 2¹¹ = 204718769 is a prime.

It is a super-2 number, since 2×204720817² = 83821225826294978, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (204720811) 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, 12273 + ... + 23665.

It is an arithmetic number, because the mean of its divisors is an integer number (15586992).

Almost surely, 2^204720817 is an apocalyptic number.

It is an amenable number.

204720817 is a deficient number, since it is larger than the sum of its proper divisors (44671055).

204720817 is a wasteful number, since it uses less digits than its factorization.

204720817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11568.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 204720817 is about 14308.0682483695. The cubic root of 204720817 is about 589.3690631497.

The spelling of 204720817 in words is "two hundred four million, seven hundred twenty thousand, eight hundred seventeen".