20311728 has 40 divisors (see below), whose sum is σ = 53756976. Its totient is φ = 6604800.

The previous prime is 20311723. The next prime is 20311763. The reversal of 20311728 is 82711302.

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 = 20311698 and 20311707.

It is not an unprimeable number, because it can be changed into a prime (20311723) 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, 3193 + ... + 7128.

Almost surely, 2^20311728 is an apocalyptic number.

It is an amenable number.

20311728 is an abundant number, since it is smaller than the sum of its proper divisors (33445248).

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

20311728 is a wasteful number, since it uses less digits than its factorization.

20311728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10373 (or 10367 counting only the distinct ones).

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

The square root of 20311728 is about 4506.8534478059. The cubic root of 20311728 is about 272.8447640843.

The spelling of 20311728 in words is "twenty million, three hundred eleven thousand, seven hundred twenty-eight".