1521231 has 4 divisors (see below), whose sum is σ = 2028312. Its totient is φ = 1014152.

The previous prime is 1521229. The next prime is 1521241. The reversal of 1521231 is 1321251.

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 1521231 - 2¹ = 1521229 is a prime.

It is a super-2 number, since 2×1521231² = 4628287510722, which contains 22 as substring.

It is a D-number.

1521231 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1521231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1521241) 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 3 ways as a sum of consecutive naturals, for example, 253536 + ... + 253541.

It is an arithmetic number, because the mean of its divisors is an integer number (507078).

2^1521231 is an apocalyptic number.

1521231 is a deficient number, since it is larger than the sum of its proper divisors (507081).

1521231 is an equidigital number, since it uses as much as digits as its factorization.

1521231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507080.

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

The square root of 1521231 is about 1233.3819359793. The cubic root of 1521231 is about 115.0089722048.

Adding to 1521231 its reverse (1321251), we get a palindrome (2842482).

The spelling of 1521231 in words is "one million, five hundred twenty-one thousand, two hundred thirty-one".