1215115155 has 32 divisors (see below), whose sum is σ = 2212902720. Its totient is φ = 632252160.

The previous prime is 1215115133. The next prime is 1215115157. The reversal of 1215115155 is 5515115121.

It is a happy number.

1215115155 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1215115155 - 2⁵ = 1215115123 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1215115157) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 104232 + ... + 115301.

It is an arithmetic number, because the mean of its divisors is an integer number (69153210).

Almost surely, 2^1215115155 is an apocalyptic number.

1215115155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1215115155 is a deficient number, since it is larger than the sum of its proper divisors (997787565).

1215115155 is a wasteful number, since it uses less digits than its factorization.

1215115155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219588 (or 219582 counting only the distinct ones).

The product of its digits is 1250, while the sum is 27.

The square root of 1215115155 is about 34858.5019041266. The cubic root of 1215115155 is about 1067.1017017264.

The spelling of 1215115155 in words is "one billion, two hundred fifteen million, one hundred fifteen thousand, one hundred fifty-five".