20413440 has 132 divisors (see below), whose sum is σ = 70891704. Its totient is φ = 5431296.

The previous prime is 20413409. The next prime is 20413441. The reversal of 20413440 is 4431402.

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 (20413441) 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 11 ways as a sum of consecutive naturals, for example, 45859 + ... + 46301.

Almost surely, 2^20413440 is an apocalyptic number.

20413440 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 20413440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35445852).

20413440 is an abundant number, since it is smaller than the sum of its proper divisors (50478264).

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

20413440 is a wasteful number, since it uses less digits than its factorization.

20413440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474 (or 453 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 20413440 is about 4518.1235042880. The cubic root of 20413440 is about 273.2994339610.

Adding to 20413440 its reverse (4431402), we get a palindrome (24844842).

The spelling of 20413440 in words is "twenty million, four hundred thirteen thousand, four hundred forty".