1971216 has 105 divisors (see below), whose sum is σ = 6200589. Its totient is φ = 606528.

The previous prime is 1971209. The next prime is 1971241. The reversal of 1971216 is 6121791.

The square root of 1971216 is 1404.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 291600 + 1679616 = 540^2 + 1296^2 .

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

Its product of digits (756) is a multiple of the sum of its prime divisors (18).

It is a self number, because there is not a number n which added to its sum of digits gives 1971216.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 151626 + ... + 151638.

2^1971216 is an apocalyptic number.

1971216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1971216 is the 1404-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1971216

1971216 is an abundant number, since it is smaller than the sum of its proper divisors (4229373).

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

1971216 is an equidigital number, since it uses as much as digits as its factorization.

1971216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52 (or 18 counting only the distinct ones).

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

The cubic root of 1971216 is about 125.3847558219.

It can be divided in two parts, 1971 and 216, that added together give a 7-th power (2187 = 3⁷).

The spelling of 1971216 in words is "one million, nine hundred seventy-one thousand, two hundred sixteen".