20204247 has 16 divisors (see below), whose sum is σ = 30868992. Its totient is φ = 11514720.

The previous prime is 20204243. The next prime is 20204269. The reversal of 20204247 is 74240202.

It is not a de Polignac number, because 20204247 - 2² = 20204243 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20204243) 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 15 ways as a sum of consecutive naturals, for example, 8638 + ... + 10724.

It is an arithmetic number, because the mean of its divisors is an integer number (1929312).

Almost surely, 2^20204247 is an apocalyptic number.

20204247 is a deficient number, since it is larger than the sum of its proper divisors (10664745).

20204247 is a wasteful number, since it uses less digits than its factorization.

20204247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2558.

The product of its (nonzero) digits is 896, while the sum is 21.

The square root of 20204247 is about 4494.9134585662. The cubic root of 20204247 is about 272.3626533398.

Adding to 20204247 its reverse (74240202), we get a palindrome (94444449).

The spelling of 20204247 in words is "twenty million, two hundred four thousand, two hundred forty-seven".