162531221 has 4 divisors (see below), whose sum is σ = 162571500. Its totient is φ = 162490944.

The previous prime is 162531209. The next prime is 162531223. The reversal of 162531221 is 122135261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122135261 = 37 ⋅3300953.

It can be written as a sum of positive squares in 2 ways, for example, as 46430596 + 116100625 = 6814^2 + 10775^2 .

It is a cyclic number.

It is not a de Polignac number, because 162531221 - 2⁶ = 162531157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (162531223) 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, 13316 + ... + 22413.

It is an arithmetic number, because the mean of its divisors is an integer number (40642875).

Almost surely, 2^162531221 is an apocalyptic number.

It is an amenable number.

162531221 is a deficient number, since it is larger than the sum of its proper divisors (40279).

162531221 is an equidigital number, since it uses as much as digits as its factorization.

162531221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40278.

The product of its digits is 720, while the sum is 23.

The square root of 162531221 is about 12748.7733135388. The cubic root of 162531221 is about 545.7313873718.

Adding to 162531221 its reverse (122135261), we get a palindrome (284666482).

The spelling of 162531221 in words is "one hundred sixty-two million, five hundred thirty-one thousand, two hundred twenty-one".