20028311 has 4 divisors (see below), whose sum is σ = 20050800. Its totient is φ = 20005824.

The previous prime is 20028301. The next prime is 20028341. The reversal of 20028311 is 11382002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11382002 = 2 ⋅5691001.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20028311 is a prime.

It is a super-2 number, since 2×20028311² = 802266483025442, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20028311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20028301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9851 + ... + 11708.

It is an arithmetic number, because the mean of its divisors is an integer number (5012700).

Almost surely, 2^20028311 is an apocalyptic number.

20028311 is a deficient number, since it is larger than the sum of its proper divisors (22489).

20028311 is an equidigital number, since it uses as much as digits as its factorization.

20028311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22488.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 20028311 is about 4475.3001016692. The cubic root of 20028311 is about 271.5697810678.

The spelling of 20028311 in words is "twenty million, twenty-eight thousand, three hundred eleven".