20727440 has 40 divisors (see below), whose sum is σ = 48653880. Its totient is φ = 8211456.

The previous prime is 20727433. The next prime is 20727449. The reversal of 20727440 is 4472702.

It can be written as a sum of positive squares in 4 ways, for example, as 2715904 + 18011536 = 1648^2 + 4244^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20727449) 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, 7532 + ... + 9908.

It is an arithmetic number, because the mean of its divisors is an integer number (1216347).

Almost surely, 2^20727440 is an apocalyptic number.

20727440 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 20727440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24326940).

20727440 is an abundant number, since it is smaller than the sum of its proper divisors (27926440).

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

20727440 is a wasteful number, since it uses less digits than its factorization.

20727440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2499 (or 2493 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 26.

The square root of 20727440 is about 4552.7398344294. The cubic root of 20727440 is about 274.6936091751.

The spelling of 20727440 in words is "twenty million, seven hundred twenty-seven thousand, four hundred forty".