20489040 has 240 divisors, whose sum is σ = 81244800. Its totient is φ = 4561920.

The previous prime is 20489023. The next prime is 20489059. The reversal of 20489040 is 4098402.

It is a tau number, because it is divible by the number of its divisors (240).

It is a junction number, because it is equal to n+sod(n) for n = 20488995 and 20489013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 102861 + ... + 103059.

It is an arithmetic number, because the mean of its divisors is an integer number (338520).

Almost surely, 2^20489040 is an apocalyptic number.

20489040 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 20489040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40622400).

20489040 is an abundant number, since it is smaller than the sum of its proper divisors (60755760).

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

20489040 is a wasteful number, since it uses less digits than its factorization.

20489040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20489040 is about 4526.4820777288. The cubic root of 20489040 is about 273.6364012304.

The spelling of 20489040 in words is "twenty million, four hundred eighty-nine thousand, forty".