20731128 has 64 divisors (see below), whose sum is σ = 59529600. Its totient is φ = 5950080.

The previous prime is 20731127. The next prime is 20731129. The reversal of 20731128 is 82113702.

It is an interprime number because it is at equal distance from previous prime (20731127) and next prime (20731129).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 20731098 and 20731107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20731121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2950 + ... + 7082.

It is an arithmetic number, because the mean of its divisors is an integer number (930150).

Almost surely, 2^20731128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20731128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29764800).

20731128 is an abundant number, since it is smaller than the sum of its proper divisors (38798472).

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

20731128 is a wasteful number, since it uses less digits than its factorization.

20731128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4172 (or 4168 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20731128 is about 4553.1448472457. The cubic root of 20731128 is about 274.7099001394.

The spelling of 20731128 in words is "twenty million, seven hundred thirty-one thousand, one hundred twenty-eight".