1531221 has 8 divisors (see below), whose sum is σ = 2055264. Its totient is φ = 1014000.

The previous prime is 1531217. The next prime is 1531253. The reversal of 1531221 is 1221351.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1531221 - 2² = 1531217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1531221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1155 + ... + 2096.

It is an arithmetic number, because the mean of its divisors is an integer number (256908).

2^1531221 is an apocalyptic number.

It is an amenable number.

1531221 is a deficient number, since it is larger than the sum of its proper divisors (524043).

1531221 is a wasteful number, since it uses less digits than its factorization.

1531221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3411.

The product of its digits is 60, while the sum is 15.

The square root of 1531221 is about 1237.4251492515. The cubic root of 1531221 is about 115.2601796634.

Adding to 1531221 its reverse (1221351), we get a palindrome (2752572).

The spelling of 1531221 in words is "one million, five hundred thirty-one thousand, two hundred twenty-one".