20163440 has 60 divisors (see below), whose sum is σ = 51553992. Its totient is φ = 7328640.

The previous prime is 20163397. The next prime is 20163443. The reversal of 20163440 is 4436102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20163443) 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, 8639 + ... + 10721.

Almost surely, 2^20163440 is an apocalyptic number.

20163440 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 20163440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25776996).

20163440 is an abundant number, since it is smaller than the sum of its proper divisors (31390552).

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

20163440 is a wasteful number, since it uses less digits than its factorization.

20163440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2118 (or 2101 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 20163440 is about 4490.3719222354. The cubic root of 20163440 is about 272.1791639673.

Adding to 20163440 its reverse (4436102), we get a palindrome (24599542).

The spelling of 20163440 in words is "twenty million, one hundred sixty-three thousand, four hundred forty".