1861216 has 36 divisors (see below), whose sum is σ = 4266108. Its totient is φ = 796992.

The previous prime is 1861187. The next prime is 1861219. The reversal of 1861216 is 6121681.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861219) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 975 + ... + 2161.

It is an arithmetic number, because the mean of its divisors is an integer number (118503).

2^1861216 is an apocalyptic number.

1861216 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 1861216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2133054).

1861216 is an abundant number, since it is smaller than the sum of its proper divisors (2404892).

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

1861216 is a wasteful number, since it uses less digits than its factorization.

1861216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1211 (or 1196 counting only the distinct ones).

The product of its digits is 576, while the sum is 25.

The square root of 1861216 is about 1364.2639040889. The cubic root of 1861216 is about 123.0076889458.

Adding to 1861216 its reverse (6121681), we get a palindrome (7982897).

It can be divided in two parts, 18612 and 16, that multiplied together give a palindrome (297792).

The spelling of 1861216 in words is "one million, eight hundred sixty-one thousand, two hundred sixteen".