1215221673 has 32 divisors (see below), whose sum is σ = 1712954880. Its totient is φ = 765296640.

The previous prime is 1215221671. The next prime is 1215221699. The reversal of 1215221673 is 3761225121.

It is not a de Polignac number, because 1215221673 - 2¹ = 1215221671 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1215221673.

It is not an unprimeable number, because it can be changed into a prime (1215221671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1169088 + ... + 1170126.

It is an arithmetic number, because the mean of its divisors is an integer number (53529840).

Almost surely, 2^1215221673 is an apocalyptic number.

It is an amenable number.

1215221673 is a deficient number, since it is larger than the sum of its proper divisors (497733207).

1215221673 is a wasteful number, since it uses less digits than its factorization.

1215221673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1377.

The product of its digits is 5040, while the sum is 30.

The square root of 1215221673 is about 34860.0297332059. The cubic root of 1215221673 is about 1067.1328818214.

Adding to 1215221673 its reverse (3761225121), we get a palindrome (4976446794).

The spelling of 1215221673 in words is "one billion, two hundred fifteen million, two hundred twenty-one thousand, six hundred seventy-three".