1215808 has 42 divisors (see below), whose sum is σ = 2668778. Its totient is φ = 549120.

The previous prime is 1215787. The next prime is 1215827. The reversal of 1215808 is 8085121.

It can be written as a sum of positive squares in only one way, i.e., 937024 + 278784 = 968^2 + 528^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7666 + ... + 7822.

2^1215808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1215808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1334389).

1215808 is an abundant number, since it is smaller than the sum of its proper divisors (1452970).

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

1215808 is a wasteful number, since it uses less digits than its factorization.

1215808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 25.

The square root of 1215808 is about 1102.6368395805. The cubic root of 1215808 is about 106.7304479655.

It can be divided in two parts, 121 and 5808, that added together give a square (5929 = 77²).

The spelling of 1215808 in words is "one million, two hundred fifteen thousand, eight hundred eight".