20723040 has 288 divisors, whose sum is σ = 80904096. Its totient is φ = 4976640.

The previous prime is 20723029. The next prime is 20723041. The reversal of 20723040 is 4032702.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20723041) 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 47 ways as a sum of consecutive naturals, for example, 505420 + ... + 505460.

It is an arithmetic number, because the mean of its divisors is an integer number (280917).

Almost surely, 2^20723040 is an apocalyptic number.

20723040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20723040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40452048).

20723040 is an abundant number, since it is smaller than the sum of its proper divisors (60181056).

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

20723040 is a wasteful number, since it uses less digits than its factorization.

20723040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 18.

The square root of 20723040 is about 4552.2565832782. The cubic root of 20723040 is about 274.6741705724.

Adding to 20723040 its reverse (4032702), we get a palindrome (24755742).

The spelling of 20723040 in words is "twenty million, seven hundred twenty-three thousand, forty".