20904447 has 32 divisors (see below), whose sum is σ = 31150080. Its totient is φ = 12418560.

The previous prime is 20904439. The next prime is 20904461. The reversal of 20904447 is 74440902.

It is not a de Polignac number, because 20904447 - 2³ = 20904439 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20904437) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 61863 + ... + 62199.

It is an arithmetic number, because the mean of its divisors is an integer number (973440).

Almost surely, 2^20904447 is an apocalyptic number.

20904447 is a deficient number, since it is larger than the sum of its proper divisors (10245633).

20904447 is a wasteful number, since it uses less digits than its factorization.

20904447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423.

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 20904447 is about 4572.1381212732. The cubic root of 20904447 is about 275.4733313887.

The spelling of 20904447 in words is "twenty million, nine hundred four thousand, four hundred forty-seven".