220531 has 4 divisors (see below), whose sum is σ = 223272. Its totient is φ = 217792.

The previous prime is 220529. The next prime is 220537. The reversal of 220531 is 135022.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135022 = 2 ⋅67511.

It is not a de Polignac number, because 220531 - 2¹ = 220529 is a prime.

It is a super-2 number, since 2×220531² = 97267843922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220537) 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, 1246 + ... + 1411.

It is an arithmetic number, because the mean of its divisors is an integer number (55818).

2²²⁰⁵³¹ is an apocalyptic number.

220531 is a deficient number, since it is larger than the sum of its proper divisors (2741).

220531 is an equidigital number, since it uses as much as digits as its factorization.

220531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2740.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 220531 is about 469.6072827374. The cubic root of 220531 is about 60.4166372308.

Adding to 220531 its reverse (135022), we get a palindrome (355553).

The spelling of 220531 in words is "two hundred twenty thousand, five hundred thirty-one".