20506231 has 4 divisors (see below), whose sum is σ = 20538864. Its totient is φ = 20473600.

The previous prime is 20506201. The next prime is 20506243. The reversal of 20506231 is 13260502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20506231 - 2¹⁵ = 20473463 is a prime.

It is a super-2 number, since 2×20506231² = 841011019650722, 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 = 20506199 and 20506208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506201) 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, 15355 + ... + 16636.

It is an arithmetic number, because the mean of its divisors is an integer number (5134716).

Almost surely, 2^20506231 is an apocalyptic number.

20506231 is a deficient number, since it is larger than the sum of its proper divisors (32633).

20506231 is an equidigital number, since it uses as much as digits as its factorization.

20506231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32632.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 20506231 is about 4528.3806156285. The cubic root of 20506231 is about 273.7129099128.

Adding to 20506231 its reverse (13260502), we get a palindrome (33766733).

It can be divided in two parts, 2050623 and 1, that added together give a square (2050624 = 1432²).

The spelling of 20506231 in words is "twenty million, five hundred six thousand, two hundred thirty-one".