1215220544 has 28 divisors (see below), whose sum is σ = 2538374400. Its totient is φ = 575630208.

The previous prime is 1215220543. The next prime is 1215220577. The reversal of 1215220544 is 4450225121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215220541) 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, 498464 + ... + 500895.

Almost surely, 2^1215220544 is an apocalyptic number.

It is an amenable number.

1215220544 is an abundant number, since it is smaller than the sum of its proper divisors (1323153856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1215220544 is an equidigital number, since it uses as much as digits as its factorization.

1215220544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 999390 (or 999380 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 26.

The square root of 1215220544 is about 34860.0135398712. The cubic root of 1215220544 is about 1067.1325513485.

Adding to 1215220544 its reverse (4450225121), we get a palindrome (5665445665).

The spelling of 1215220544 in words is "one billion, two hundred fifteen million, two hundred twenty thousand, five hundred forty-four".