20472945 has 16 divisors (see below), whose sum is σ = 33519552. Its totient is φ = 10664640.

The previous prime is 20472943. The next prime is 20472971. The reversal of 20472945 is 54927402.

It is not a de Polignac number, because 20472945 - 2¹ = 20472943 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20472943) 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, 15226 + ... + 16515.

It is an arithmetic number, because the mean of its divisors is an integer number (2094972).

Almost surely, 2^20472945 is an apocalyptic number.

It is an amenable number.

20472945 is a deficient number, since it is larger than the sum of its proper divisors (13046607).

20472945 is a wasteful number, since it uses less digits than its factorization.

20472945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31792.

The product of its (nonzero) digits is 20160, while the sum is 33.

The square root of 20472945 is about 4524.7038577127. The cubic root of 20472945 is about 273.5647315052.

The spelling of 20472945 in words is "twenty million, four hundred seventy-two thousand, nine hundred forty-five".