20447040 has 168 divisors, whose sum is σ = 69677280. Its totient is φ = 5078016.

The previous prime is 20447003. The next prime is 20447057. The reversal of 20447040 is 4074402.

It is a junction number, because it is equal to n+sod(n) for n = 20446998 and 20447016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 346531 + ... + 346589.

Almost surely, 2^20447040 is an apocalyptic number.

20447040 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 20447040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34838640).

20447040 is an abundant number, since it is smaller than the sum of its proper divisors (49230240).

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

20447040 is a wasteful number, since it uses less digits than its factorization.

20447040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 21.

The square root of 20447040 is about 4521.8403333156. The cubic root of 20447040 is about 273.4492997248.

The spelling of 20447040 in words is "twenty million, four hundred forty-seven thousand, forty".