20027831 has 4 divisors (see below), whose sum is σ = 20138664. Its totient is φ = 19917000.

The previous prime is 20027801. The next prime is 20027851. The reversal of 20027831 is 13872002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13872002 = 2 ⋅6936001.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20027831 is a prime.

It is a super-2 number, since 2×20027831² = 802228029129122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20027797 and 20027806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20027801) 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, 55145 + ... + 55506.

It is an arithmetic number, because the mean of its divisors is an integer number (5034666).

Almost surely, 2^20027831 is an apocalyptic number.

20027831 is a deficient number, since it is larger than the sum of its proper divisors (110833).

20027831 is a wasteful number, since it uses less digits than its factorization.

20027831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110832.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 20027831 is about 4475.2464736593. The cubic root of 20027831 is about 271.5676115632.

Adding to 20027831 its reverse (13872002), we get a palindrome (33899833).

The spelling of 20027831 in words is "twenty million, twenty-seven thousand, eight hundred thirty-one".