1211616 has 72 divisors (see below), whose sum is σ = 3944304. Its totient is φ = 345600.

The previous prime is 1211603. The next prime is 1211621. The reversal of 1211616 is 6161121.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

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 a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1716 + ... + 2316.

It is an arithmetic number, because the mean of its divisors is an integer number (54782).

2^1211616 is an apocalyptic number.

1211616 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 1211616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1972152).

1211616 is an abundant number, since it is smaller than the sum of its proper divisors (2732688).

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

1211616 is a wasteful number, since it uses less digits than its factorization.

1211616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624 (or 613 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

The square root of 1211616 is about 1100.7343003650. The cubic root of 1211616 is about 106.6076409543.

Adding to 1211616 its reverse (6161121), we get a palindrome (7372737).

It can be divided in two parts, 12 and 11616, that added together give a triangular number (11628 = T₁₅₂).

The spelling of 1211616 in words is "one million, two hundred eleven thousand, six hundred sixteen".