20181456 has 60 divisors (see below), whose sum is σ = 56798820. Its totient is φ = 6689280.

The previous prime is 20181451. The next prime is 20181457. The reversal of 20181456 is 65418102.

20181456 is a `hidden beast` number, since 201 + 8 + 1 + 456 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3240000 + 16941456 = 1800^2 + 4116^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20181451) 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 11 ways as a sum of consecutive naturals, for example, 38476 + ... + 38996.

It is an arithmetic number, because the mean of its divisors is an integer number (946647).

Almost surely, 2^20181456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20181456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28399410).

20181456 is an abundant number, since it is smaller than the sum of its proper divisors (36617364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20181456 is a wasteful number, since it uses less digits than its factorization.

20181456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804 (or 795 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 20181456 is about 4492.3775442409. The cubic root of 20181456 is about 272.2602037121.

Adding to 20181456 its reverse (65418102), we get a palindrome (85599558).

It can be divided in two parts, 20 and 181456, that added together give a square (181476 = 426²).

The spelling of 20181456 in words is "twenty million, one hundred eighty-one thousand, four hundred fifty-six".