20247040 has 80 divisors (see below), whose sum is σ = 53032320. Its totient is φ = 7352320.

The previous prime is 20247037. The next prime is 20247041. The reversal of 20247040 is 4074202.

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

It is a junction number, because it is equal to n+sod(n) for n = 20246999 and 20247017.

It is not an unprimeable number, because it can be changed into a prime (20247041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27801 + ... + 28519.

It is an arithmetic number, because the mean of its divisors is an integer number (662904).

Almost surely, 2^20247040 is an apocalyptic number.

20247040 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 20247040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26516160).

20247040 is an abundant number, since it is smaller than the sum of its proper divisors (32785280).

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

20247040 is an equidigital number, since it uses as much as digits as its factorization.

20247040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753 (or 737 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 19.

The square root of 20247040 is about 4499.6710990916. The cubic root of 20247040 is about 272.5548075938.

The spelling of 20247040 in words is "twenty million, two hundred forty-seven thousand, forty".