1021216 has 48 divisors (see below), whose sum is σ = 2370816. Its totient is φ = 423936.

The previous prime is 1021199. The next prime is 1021217. The reversal of 1021216 is 6121201.

It is an Ulam number.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 1021196 and 1021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10480 + ... + 10576.

It is an arithmetic number, because the mean of its divisors is an integer number (49392).

2^1021216 is an apocalyptic number.

1021216 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 1021216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1185408).

1021216 is an abundant number, since it is smaller than the sum of its proper divisors (1349600).

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

1021216 is an equidigital number, since it uses as much as digits as its factorization.

1021216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1021216 is about 1010.5523242267. The cubic root of 1021216 is about 100.7022568095.

Adding to 1021216 its reverse (6121201), we get a palindrome (7142417).

The spelling of 1021216 in words is "one million, twenty-one thousand, two hundred sixteen".