1645403415444 has 144 divisors (see below), whose sum is σ = 4322240674752. Its totient is φ = 527377568256.

The previous prime is 1645403415443. The next prime is 1645403415493. The reversal of 1645403415444 is 4445143045461.

It is a happy number.

1645403415444 is a `hidden beast` number, since 1 + 6 + 454 + 0 + 3 + 4 + 154 + 44 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 1645403415444.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645403415443) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 198404562 + ... + 198412854.

Almost surely, 2^{1645403415444} 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 1645403415444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2161120337376).

1645403415444 is an abundant number, since it is smaller than the sum of its proper divisors (2676837259308).

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

1645403415444 is a wasteful number, since it uses less digits than its factorization.

1645403415444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10326 (or 10321 counting only the distinct ones).

The product of its (nonzero) digits is 1843200, while the sum is 45.

The spelling of 1645403415444 in words is "one trillion, six hundred forty-five billion, four hundred three million, four hundred fifteen thousand, four hundred forty-four".