20542231 has 4 divisors (see below), whose sum is σ = 20563600. Its totient is φ = 20520864.

The previous prime is 20542213. The next prime is 20542253. The reversal of 20542231 is 13224502.

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 20542231 - 2¹³ = 20534039 is a prime.

It is a super-2 number, since 2×20542231² = 843966508914722, 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 = 20542199 and 20542208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20542201) 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, 9171 + ... + 11188.

It is an arithmetic number, because the mean of its divisors is an integer number (5140900).

Almost surely, 2^20542231 is an apocalyptic number.

20542231 is a deficient number, since it is larger than the sum of its proper divisors (21369).

20542231 is a wasteful number, since it uses less digits than its factorization.

20542231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21368.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20542231 is about 4532.3538034889. The cubic root of 20542231 is about 273.8729897787.

Adding to 20542231 its reverse (13224502), we get a palindrome (33766733).

It can be divided in two parts, 205 and 42231, that added together give a square (42436 = 206²).

The spelling of 20542231 in words is "twenty million, five hundred forty-two thousand, two hundred thirty-one".