1645604064 has 144 divisors (see below), whose sum is σ = 5056506000. Its totient is φ = 504649728.

The previous prime is 1645604047. The next prime is 1645604071. The reversal of 1645604064 is 4604065461.

1645604064 is a `hidden beast` number, since 1 + 6 + 45 + 604 + 0 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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, 1568212 + ... + 1569260.

It is an arithmetic number, because the mean of its divisors is an integer number (35114625).

Almost surely, 2^1645604064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645604064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2528253000).

1645604064 is an abundant number, since it is smaller than the sum of its proper divisors (3410901936).

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

1645604064 is a wasteful number, since it uses less digits than its factorization.

1645604064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1497 (or 1486 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 1645604064 is about 40566.0457032726. The cubic root of 1645604064 is about 1180.6154177513.

The spelling of 1645604064 in words is "one billion, six hundred forty-five million, six hundred four thousand, sixty-four".