1215501105 has 128 divisors (see below), whose sum is σ = 2588544000. Its totient is φ = 482291712.

The previous prime is 1215501101. The next prime is 1215501151. The reversal of 1215501105 is 5011055121.

It is not a de Polignac number, because 1215501105 - 2² = 1215501101 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1215501101) 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 127 ways as a sum of consecutive naturals, for example, 1136511 + ... + 1137579.

It is an arithmetic number, because the mean of its divisors is an integer number (20223000).

Almost surely, 2^1215501105 is an apocalyptic number.

1215501105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1215501105 is an abundant number, since it is smaller than the sum of its proper divisors (1373042895).

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

1215501105 is a wasteful number, since it uses less digits than its factorization.

1215501105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1128 (or 1114 counting only the distinct ones).

The product of its (nonzero) digits is 250, while the sum is 21.

The square root of 1215501105 is about 34864.0374167996. The cubic root of 1215501105 is about 1067.2146688811.

Adding to 1215501105 its reverse (5011055121), we get a palindrome (6226556226).

The spelling of 1215501105 in words is "one billion, two hundred fifteen million, five hundred one thousand, one hundred five".