1645636608 has 352 divisors, whose sum is σ = 6084011520. Its totient is φ = 426885120.

The previous prime is 1645636561. The next prime is 1645636613. The reversal of 1645636608 is 8066365461.

1645636608 is a `hidden beast` number, since 1 + 6 + 4 + 5 + 6 + 36 + 608 = 666.

It is a tau number, because it is divible by the number of its divisors (352).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2128510 + ... + 2129282.

Almost surely, 2^1645636608 is an apocalyptic number.

1645636608 is a gapful number since it is divisible by the number (18) 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 1645636608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3042005760).

1645636608 is an abundant number, since it is smaller than the sum of its proper divisors (4438374912).

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

1645636608 is a wasteful number, since it uses less digits than its factorization.

1645636608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820 (or 796 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The square root of 1645636608 is about 40566.4468249316. The cubic root of 1645636608 is about 1180.6232004446.

It can be divided in two parts, 164563 and 6608, that added together give a palindrome (171171).

The spelling of 1645636608 in words is "one billion, six hundred forty-five million, six hundred thirty-six thousand, six hundred eight".