1643772 has 48 divisors (see below), whose sum is σ = 4247712. Its totient is φ = 491520.

The previous prime is 1643743. The next prime is 1643773. The reversal of 1643772 is 2773461.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a d-powerful number, because it can be written as 1 + 6⁶ + 4⁴ + 3¹³ + 7 + 7⁴ + 2⁷ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6268 + ... + 6524.

It is an arithmetic number, because the mean of its divisors is an integer number (88494).

2^1643772 is an apocalyptic number.

1643772 is a gapful number since it is divisible by the number (12) 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 1643772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2123856).

1643772 is an abundant number, since it is smaller than the sum of its proper divisors (2603940).

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

1643772 is a wasteful number, since it uses less digits than its factorization.

1643772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318 (or 316 counting only the distinct ones).

The product of its digits is 7056, while the sum is 30.

The square root of 1643772 is about 1282.0967202204. The cubic root of 1643772 is about 118.0177125570.

It can be divided in two parts, 1643 and 772, that added together give a triangular number (2415 = T₆₉).

The spelling of 1643772 in words is "one million, six hundred forty-three thousand, seven hundred seventy-two".