20181447 has 32 divisors (see below), whose sum is σ = 35132160. Its totient is φ = 11288160.

The previous prime is 20181437. The next prime is 20181451. The reversal of 20181447 is 74418102.

It is not a de Polignac number, because 20181447 - 2⁸ = 20181191 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 20181447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20181437) 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, 1248 + ... + 6474.

It is an arithmetic number, because the mean of its divisors is an integer number (1097880).

Almost surely, 2^20181447 is an apocalyptic number.

20181447 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

20181447 is a deficient number, since it is larger than the sum of its proper divisors (14950713).

20181447 is a wasteful number, since it uses less digits than its factorization.

20181447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5260 (or 5254 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 20181447 is about 4492.3765425440. The cubic root of 20181447 is about 272.2601632403.

Adding to 20181447 its reverse (74418102), we get a palindrome (94599549).

The spelling of 20181447 in words is "twenty million, one hundred eighty-one thousand, four hundred forty-seven".