1215433221 has 8 divisors (see below), whose sum is σ = 1620843744. Its totient is φ = 810155760.

The previous prime is 1215433189. The next prime is 1215433231. The reversal of 1215433221 is 1223345121.

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

It is not a de Polignac number, because 1215433221 - 2⁵ = 1215433189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1215433191 and 1215433200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215433231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9531 + ... + 50216.

It is an arithmetic number, because the mean of its divisors is an integer number (202605468).

Almost surely, 2^1215433221 is an apocalyptic number.

It is an amenable number.

1215433221 is a deficient number, since it is larger than the sum of its proper divisors (405410523).

1215433221 is an equidigital number, since it uses as much as digits as its factorization.

1215433221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66531.

The product of its digits is 1440, while the sum is 24.

The square root of 1215433221 is about 34863.0638498684. The cubic root of 1215433221 is about 1067.1948010398.

Adding to 1215433221 its reverse (1223345121), we get a palindrome (2438778342).

The spelling of 1215433221 in words is "one billion, two hundred fifteen million, four hundred thirty-three thousand, two hundred twenty-one".