1643041600 has 84 divisors (see below), whose sum is σ = 4060637548. Its totient is φ = 654336000.

The previous prime is 1643041579. The next prime is 1643041643. The reversal of 1643041600 is 61403461.

It can be written as a sum of positive squares in 6 ways, for example, as 135117376 + 1507924224 = 11624^2 + 38832^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 383470 + ... + 387730.

Almost surely, 2^1643041600 is an apocalyptic number.

1643041600 is a gapful number since it is divisible by the number (10) 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 1643041600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2030318774).

1643041600 is an abundant number, since it is smaller than the sum of its proper divisors (2417595948).

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

1643041600 is a wasteful number, since it uses less digits than its factorization.

1643041600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4524 (or 4509 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1643041600 is about 40534.4495460343. The cubic root of 1643041600 is about 1180.0022981857.

The spelling of 1643041600 in words is "one billion, six hundred forty-three million, forty-one thousand, six hundred".