1216656 has 120 divisors (see below), whose sum is σ = 4178304. Its totient is φ = 322560.

The previous prime is 1216619. The next prime is 1216681. The reversal of 1216656 is 6566121.

It is a happy number.

1216656 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 656 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17101 + ... + 17171.

2^1216656 is an apocalyptic number.

1216656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2089152).

1216656 is an abundant number, since it is smaller than the sum of its proper divisors (2961648).

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

1216656 is a wasteful number, since it uses less digits than its factorization.

1216656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 100 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 1216656 is about 1103.0213053246. The cubic root of 1216656 is about 106.7552562646.

Adding to 1216656 its product of digits (2160), we get a square (1218816 = 1104²).

The spelling of 1216656 in words is "one million, two hundred sixteen thousand, six hundred fifty-six".