1215541855 has 8 divisors (see below), whose sum is σ = 1591254864. Its totient is φ = 884030400.

The previous prime is 1215541849. The next prime is 1215541897. The reversal of 1215541855 is 5581455121.

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

It is not a de Polignac number, because 1215541855 - 2¹¹ = 1215539807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 11050326 + ... + 11050435.

It is an arithmetic number, because the mean of its divisors is an integer number (198906858).

Almost surely, 2^1215541855 is an apocalyptic number.

1215541855 is a deficient number, since it is larger than the sum of its proper divisors (375713009).

1215541855 is a wasteful number, since it uses less digits than its factorization.

1215541855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22100777.

The product of its digits is 40000, while the sum is 37.

The square root of 1215541855 is about 34864.6218249962. The cubic root of 1215541855 is about 1067.2265949670.

Adding to 1215541855 its reverse (5581455121), we get a palindrome (6796996976).

The spelling of 1215541855 in words is "one billion, two hundred fifteen million, five hundred forty-one thousand, eight hundred fifty-five".