1643616 has 72 divisors (see below), whose sum is σ = 5045040. Its totient is φ = 504576.

The previous prime is 1643599. The next prime is 1643617. The reversal of 1643616 is 6163461.

1643616 is a `hidden beast` number, since 1 + 6 + 43 + 616 = 666.

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

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1643616.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643617) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 3525 + ... + 3963.

It is an arithmetic number, because the mean of its divisors is an integer number (70070).

2^1643616 is an apocalyptic number.

1643616 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 1643616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2522520).

1643616 is an abundant number, since it is smaller than the sum of its proper divisors (3401424).

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

1643616 is a wasteful number, since it uses less digits than its factorization.

1643616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468 (or 457 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 1643616 is about 1282.0358809331. The cubic root of 1643616 is about 118.0139790008.

The spelling of 1643616 in words is "one million, six hundred forty-three thousand, six hundred sixteen".