1645632000 has 240 divisors, whose sum is σ = 5929332552. Its totient is φ = 438681600.

The previous prime is 1645631987. The next prime is 1645632019. The reversal of 1645632000 is 2365461.

1645632000 is a `hidden beast` number, since 1 + 6 + 456 + 3 + 200 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 620607744 + 1025024256 = 24912^2 + 32016^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 574572 + ... + 577428.

Almost surely, 2^1645632000 is an apocalyptic number.

1645632000 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 1645632000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2964666276).

1645632000 is an abundant number, since it is smaller than the sum of its proper divisors (4283700552).

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

1645632000 is an equidigital number, since it uses as much as digits as its factorization.

1645632000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2896 (or 2867 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 1645632000 is about 40566.3900291855. The cubic root of 1645632000 is about 1180.6220984765.

Adding to 1645632000 its reverse (2365461), we get a palindrome (1647997461).

The spelling of 1645632000 in words is "one billion, six hundred forty-five million, six hundred thirty-two thousand".