1215839205 has 72 divisors (see below), whose sum is σ = 2465093592. Its totient is φ = 552738816.

The previous prime is 1215839197. The next prime is 1215839213. The reversal of 1215839205 is 5029385121.

1215839205 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1215839197) and next prime (1215839213).

It can be written as a sum of positive squares in 4 ways, for example, as 89699841 + 1126139364 = 9471^2 + 33558^2 .

It is not a de Polignac number, because 1215839205 - 2³ = 1215839197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1215839205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 424137 + ... + 426993.

It is an arithmetic number, because the mean of its divisors is an integer number (34237411).

Almost surely, 2^1215839205 is an apocalyptic number.

1215839205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1215839205 is an abundant number, since it is smaller than the sum of its proper divisors (1249254387).

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

1215839205 is a wasteful number, since it uses less digits than its factorization.

1215839205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3075 (or 3065 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 1215839205 is about 34868.8859156699. The cubic root of 1215839205 is about 1067.3136107435.

The spelling of 1215839205 in words is "one billion, two hundred fifteen million, eight hundred thirty-nine thousand, two hundred five".