1215572221 has 8 divisors (see below), whose sum is σ = 1241000640. Its totient is φ = 1190304768.

The previous prime is 1215572219. The next prime is 1215572243. The reversal of 1215572221 is 1222755121.

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

It is a cyclic number.

It is not a de Polignac number, because 1215572221 - 2¹ = 1215572219 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1215572221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215572261) 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, 24921 + ... + 55246.

It is an arithmetic number, because the mean of its divisors is an integer number (155125080).

Almost surely, 2^1215572221 is an apocalyptic number.

It is an amenable number.

1215572221 is a deficient number, since it is larger than the sum of its proper divisors (25428419).

1215572221 is an equidigital number, since it uses as much as digits as its factorization.

1215572221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80483.

The product of its digits is 2800, while the sum is 28.

The square root of 1215572221 is about 34865.0573067075. The cubic root of 1215572221 is about 1067.2354818495.

The spelling of 1215572221 in words is "one billion, two hundred fifteen million, five hundred seventy-two thousand, two hundred twenty-one".