1215129808 has 20 divisors (see below), whose sum is σ = 2492803620. Its totient is φ = 571825664.

The previous prime is 1215129787. The next prime is 1215129809. The reversal of 1215129808 is 8089215121.

It can be written as a sum of positive squares in 2 ways, for example, as 523860544 + 691269264 = 22888^2 + 26292^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215129809) 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 3 ways as a sum of consecutive naturals, for example, 2233423 + ... + 2233966.

It is an arithmetic number, because the mean of its divisors is an integer number (124640181).

Almost surely, 2^1215129808 is an apocalyptic number.

It is an amenable number.

1215129808 is an abundant number, since it is smaller than the sum of its proper divisors (1277673812).

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

1215129808 is a wasteful number, since it uses less digits than its factorization.

1215129808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4467414 (or 4467408 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 37.

The square root of 1215129808 is about 34858.7120817738. The cubic root of 1215129808 is about 1067.1059910807.

The spelling of 1215129808 in words is "one billion, two hundred fifteen million, one hundred twenty-nine thousand, eight hundred eight".