20872240 has 40 divisors (see below), whose sum is σ = 48903120. Its totient is φ = 8284416.

The previous prime is 20872219. The next prime is 20872249. The reversal of 20872240 is 4227802.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (20872249) 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 7 ways as a sum of consecutive naturals, for example, 10182 + ... + 12058.

It is an arithmetic number, because the mean of its divisors is an integer number (1222578).

Almost surely, 2^20872240 is an apocalyptic number.

20872240 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 20872240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24451560).

20872240 is an abundant number, since it is smaller than the sum of its proper divisors (28030880).

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

20872240 is a wasteful number, since it uses less digits than its factorization.

20872240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2029 (or 2023 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 25.

The square root of 20872240 is about 4568.6146696783. The cubic root of 20872240 is about 275.3317868667.

It can be divided in two parts, 20872 and 240, that added together give a palindrome (21112).

The spelling of 20872240 in words is "twenty million, eight hundred seventy-two thousand, two hundred forty".