20478740 has 24 divisors (see below), whose sum is σ = 44876160. Its totient is φ = 7835168.

The previous prime is 20478739. The next prime is 20478749. The reversal of 20478740 is 4787402.

It is a junction number, because it is equal to n+sod(n) for n = 20478697 and 20478706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20478749) 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, 21800 + ... + 22719.

It is an arithmetic number, because the mean of its divisors is an integer number (1869840).

Almost surely, 2^20478740 is an apocalyptic number.

20478740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20478740 is an abundant number, since it is smaller than the sum of its proper divisors (24397420).

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

20478740 is a wasteful number, since it uses less digits than its factorization.

20478740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44551 (or 44549 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 32.

The square root of 20478740 is about 4525.3441858051. The cubic root of 20478740 is about 273.5905404946.

The spelling of 20478740 in words is "twenty million, four hundred seventy-eight thousand, seven hundred forty".