20887944 has 128 divisors (see below), whose sum is σ = 66355200. Its totient is φ = 5322240.

The previous prime is 20887939. The next prime is 20887949. The reversal of 20887944 is 44978802.

It is an interprime number because it is at equal distance from previous prime (20887939) and next prime (20887949).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 20887896 and 20887905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20887949) 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 31 ways as a sum of consecutive naturals, for example, 164409 + ... + 164535.

It is an arithmetic number, because the mean of its divisors is an integer number (518400).

Almost surely, 2^20887944 is an apocalyptic number.

20887944 is a gapful number since it is divisible by the number (24) 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 20887944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33177600).

20887944 is an abundant number, since it is smaller than the sum of its proper divisors (45467256).

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

20887944 is a wasteful number, since it uses less digits than its factorization.

20887944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243 (or 239 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 20887944 is about 4570.3330294411. Note that the first 3 decimals coincide. The cubic root of 20887944 is about 275.4008215661.

The spelling of 20887944 in words is "twenty million, eight hundred eighty-seven thousand, nine hundred forty-four".