20128740 has 48 divisors (see below), whose sum is σ = 57890112. Its totient is φ = 5222016.

The previous prime is 20128739. The next prime is 20128741. The reversal of 20128740 is 4782102.

It is an interprime number because it is at equal distance from previous prime (20128739) and next prime (20128741).

It is a self number, because there is not a number n which added to its sum of digits gives 20128740.

It is not an unprimeable number, because it can be changed into a prime (20128741) 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, 2314 + ... + 6753.

It is an arithmetic number, because the mean of its divisors is an integer number (1206044).

Almost surely, 2^20128740 is an apocalyptic number.

20128740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20128740 is an abundant number, since it is smaller than the sum of its proper divisors (37761372).

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

20128740 is a wasteful number, since it uses less digits than its factorization.

20128740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9116 (or 9114 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 20128740 is about 4486.5064359700. The cubic root of 20128740 is about 272.0229399626.

The spelling of 20128740 in words is "twenty million, one hundred twenty-eight thousand, seven hundred forty".