20663040 has 72 divisors (see below), whose sum is σ = 66004848. Its totient is φ = 5509120.

The previous prime is 20663017. The next prime is 20663047. The reversal of 20663040 is 4036602.

It is a super-2 number, since 2×20663040² = 853922444083200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20662998 and 20663016.

It is not an unprimeable number, because it can be changed into a prime (20663047) 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, 1150 + ... + 6530.

It is an arithmetic number, because the mean of its divisors is an integer number (916734).

Almost surely, 2^20663040 is an apocalyptic number.

20663040 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 20663040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33002424).

20663040 is an abundant number, since it is smaller than the sum of its proper divisors (45341808).

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

20663040 is an equidigital number, since it uses as much as digits as its factorization.

20663040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5405 (or 5391 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 20663040 is about 4545.6616680083. The cubic root of 20663040 is about 274.4088237040.

Adding to 20663040 its reverse (4036602), we get a palindrome (24699642).

The spelling of 20663040 in words is "twenty million, six hundred sixty-three thousand, forty".