1645202440000 has 420 divisors, whose sum is σ = 4762642341600. Its totient is φ = 562047360000.

The previous prime is 1645202439977. The next prime is 1645202440001. The reversal of 1645202440000 is 442025461.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645202440001) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 609558651 + ... + 609561349.

Almost surely, 2^{1645202440000} is an apocalyptic number.

1645202440000 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 1645202440000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2381321170800).

1645202440000 is an abundant number, since it is smaller than the sum of its proper divisors (3117439901600).

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

1645202440000 is an equidigital number, since it uses as much as digits as its factorization.

1645202440000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3056 (or 3024 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 28.

Adding to 1645202440000 its reverse (442025461), we get a palindrome (1645644465461).

The spelling of 1645202440000 in words is "one trillion, six hundred forty-five billion, two hundred two million, four hundred forty thousand".