20204657 has 16 divisors (see below), whose sum is σ = 23352000. Its totient is φ = 17288640.

The previous prime is 20204647. The next prime is 20204659. The reversal of 20204657 is 75640202.

It is a cyclic number.

It is not a de Polignac number, because 20204657 - 2⁴ = 20204641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20204659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57719 + ... + 58067.

It is an arithmetic number, because the mean of its divisors is an integer number (1459500).

Almost surely, 2^20204657 is an apocalyptic number.

It is an amenable number.

20204657 is a deficient number, since it is larger than the sum of its proper divisors (3147343).

20204657 is a wasteful number, since it uses less digits than its factorization.

20204657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656.

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 20204657 is about 4494.9590654421. The cubic root of 20204657 is about 272.3644956576.

Adding to 20204657 its reverse (75640202), we get a palindrome (95844859).

The spelling of 20204657 in words is "twenty million, two hundred four thousand, six hundred fifty-seven".