12221531 has 6 divisors (see below), whose sum is σ = 14216940. Its totient is φ = 10475556.

The previous prime is 12221527. The next prime is 12221543. The reversal of 12221531 is 13512221.

It is a happy number.

It is not a de Polignac number, because 12221531 - 2² = 12221527 is a prime.

It is a super-2 number, since 2×12221531² = 298731639967922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12221431) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 124661 + ... + 124758.

It is an arithmetic number, because the mean of its divisors is an integer number (2369490).

Almost surely, 2^12221531 is an apocalyptic number.

12221531 is a deficient number, since it is larger than the sum of its proper divisors (1995409).

12221531 is an equidigital number, since it uses as much as digits as its factorization.

12221531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249433 (or 249426 counting only the distinct ones).

The product of its digits is 120, while the sum is 17.

The square root of 12221531 is about 3495.9306343233. The cubic root of 12221531 is about 230.3430985202.

Adding to 12221531 its reverse (13512221), we get a palindrome (25733752).

The spelling of 12221531 in words is "twelve million, two hundred twenty-one thousand, five hundred thirty-one".