20536440 has 64 divisors (see below), whose sum is σ = 62791200. Its totient is φ = 5371392.

The previous prime is 20536429. The next prime is 20536457. The reversal of 20536440 is 4463502.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20536440.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 4746 + ... + 7974.

Almost surely, 2^20536440 is an apocalyptic number.

20536440 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 20536440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31395600).

20536440 is an abundant number, since it is smaller than the sum of its proper divisors (42254760).

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

20536440 is a wasteful number, since it uses less digits than its factorization.

20536440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3296 (or 3292 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 24.

The square root of 20536440 is about 4531.7149071847. The cubic root of 20536440 is about 273.8472517833.

Adding to 20536440 its reverse (4463502), we get a palindrome (24999942).

The spelling of 20536440 in words is "twenty million, five hundred thirty-six thousand, four hundred forty".