20461840 has 80 divisors (see below), whose sum is σ = 55353600. Its totient is φ = 6888960.

The previous prime is 20461823. The next prime is 20461843. The reversal of 20461840 is 4816402.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (20461843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33861 + ... + 34459.

It is an arithmetic number, because the mean of its divisors is an integer number (691920).

Almost surely, 2^20461840 is an apocalyptic number.

20461840 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 20461840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27676800).

20461840 is an abundant number, since it is smaller than the sum of its proper divisors (34891760).

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

20461840 is a wasteful number, since it uses less digits than its factorization.

20461840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 680 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 20461840 is about 4523.4765391234. The cubic root of 20461840 is about 273.5152599417.

The spelling of 20461840 in words is "twenty million, four hundred sixty-one thousand, eight hundred forty".