20556447 has 16 divisors (see below), whose sum is σ = 28489440. Its totient is φ = 13168512.

The previous prime is 20556433. The next prime is 20556467. The reversal of 20556447 is 74465502.

It is not a de Polignac number, because 20556447 - 2⁸ = 20556191 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20556407) 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, 23673 + ... + 24525.

It is an arithmetic number, because the mean of its divisors is an integer number (1780590).

Almost surely, 2^20556447 is an apocalyptic number.

20556447 is a deficient number, since it is larger than the sum of its proper divisors (7932993).

20556447 is a wasteful number, since it uses less digits than its factorization.

20556447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1162.

The product of its (nonzero) digits is 33600, while the sum is 33.

The square root of 20556447 is about 4533.9218122945. The cubic root of 20556447 is about 273.9361520296.

The spelling of 20556447 in words is "twenty million, five hundred fifty-six thousand, four hundred forty-seven".