1643342400 has 756 divisors, whose sum is σ = 7246615428. Its totient is φ = 350945280.

The previous prime is 1643342381. The next prime is 1643342401. The reversal of 1643342400 is 42433461.

It can be written as a sum of positive squares in 6 ways, for example, as 4064256 + 1639278144 = 2016^2 + 40488^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643342401) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 11995132 + ... + 11995268.

Almost surely, 2^1643342400 is an apocalyptic number.

1643342400 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 1643342400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3623307714).

1643342400 is an abundant number, since it is smaller than the sum of its proper divisors (5603273028).

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

1643342400 is a wasteful number, since it uses less digits than its factorization.

1643342400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 1643342400 is about 40538.1598003659. The cubic root of 1643342400 is about 1180.0743034701.

Adding to 1643342400 its reverse (42433461), we get a palindrome (1685775861).

The spelling of 1643342400 in words is "one billion, six hundred forty-three million, three hundred forty-two thousand, four hundred".