1217916 has 72 divisors (see below), whose sum is σ = 3669120. Its totient is φ = 346032.

The previous prime is 1217903. The next prime is 1217917. The reversal of 1217916 is 6197121.

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

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1217916.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6715 + ... + 6893.

It is an arithmetic number, because the mean of its divisors is an integer number (50960).

2^1217916 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 1217916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1834560).

1217916 is an abundant number, since it is smaller than the sum of its proper divisors (2451204).

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

1217916 is a wasteful number, since it uses less digits than its factorization.

1217916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205 (or 191 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 1217916 is about 1103.5923160298. The cubic root of 1217916 is about 106.7920963726.

The spelling of 1217916 in words is "one million, two hundred seventeen thousand, nine hundred sixteen".