20415040 has 56 divisors (see below), whose sum is σ = 49084992. Its totient is φ = 8087040.

The previous prime is 20415037. The next prime is 20415041. The reversal of 20415040 is 4051402.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (20415041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41677 + ... + 42163.

Almost surely, 2^20415040 is an apocalyptic number.

20415040 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 20415040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24542496).

20415040 is an abundant number, since it is smaller than the sum of its proper divisors (28669952).

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

20415040 is a wasteful number, since it uses less digits than its factorization.

20415040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 635 (or 625 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 20415040 is about 4518.3005654781. The cubic root of 20415040 is about 273.3065741535.

Adding to 20415040 its reverse (4051402), we get a palindrome (24466442).

The spelling of 20415040 in words is "twenty million, four hundred fifteen thousand, forty".