1645066501600 has 144 divisors (see below), whose sum is σ = 4127337396000. Its totient is φ = 639810938880.

The previous prime is 1645066501583. The next prime is 1645066501601. The reversal of 1645066501600 is 61056605461.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645066501601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45832461 + ... + 45868339.

It is an arithmetic number, because the mean of its divisors is an integer number (28662065250).

Almost surely, 2^{1645066501600} is an apocalyptic number.

1645066501600 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 1645066501600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2063668698000).

1645066501600 is an abundant number, since it is smaller than the sum of its proper divisors (2482270894400).

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

1645066501600 is a wasteful number, since it uses less digits than its factorization.

1645066501600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37485 (or 37472 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 40.

The spelling of 1645066501600 in words is "one trillion, six hundred forty-five billion, sixty-six million, five hundred one thousand, six hundred".