1643216 has 10 divisors (see below), whose sum is σ = 3183762. Its totient is φ = 821600.

The previous prime is 1643197. The next prime is 1643219. The reversal of 1643216 is 6123461.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1449616 + 193600 = 1204^2 + 440^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1643191 and 1643200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51335 + ... + 51366.

2^1643216 is an apocalyptic number.

1643216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1643216 is a deficient number, since it is larger than the sum of its proper divisors (1540546).

1643216 is a wasteful number, since it uses less digits than its factorization.

1643216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102709 (or 102703 counting only the distinct ones).

The product of its digits is 864, while the sum is 23.

The square root of 1643216 is about 1281.8798695666. The cubic root of 1643216 is about 118.0044047001.

Adding to 1643216 its reverse (6123461), we get a palindrome (7766677).

The spelling of 1643216 in words is "one million, six hundred forty-three thousand, two hundred sixteen".