1645502791680 has 760 divisors, whose sum is σ = 6440299565040. Its totient is φ = 398626652160.

The previous prime is 1645502791649. The next prime is 1645502791717. The reversal of 1645502791680 is 861972055461.

It is a happy number.

1645502791680 is a `hidden beast` number, since 1 + 6 + 4 + 5 + 502 + 79 + 1 + 68 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1167850816 + ... + 1167852224.

Almost surely, 2^{1645502791680} is an apocalyptic number.

1645502791680 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 1645502791680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3220149782520).

1645502791680 is an abundant number, since it is smaller than the sum of its proper divisors (4794796773360).

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

1645502791680 is an frugal number, since it uses more digits than its factorization.

1645502791680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1473 (or 1430 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 1645502791680 in words is "one trillion, six hundred forty-five billion, five hundred two million, seven hundred ninety-one thousand, six hundred eighty".