1645503582420 has 144 divisors (see below), whose sum is σ = 5017620299328. Its totient is φ = 436495749120.

The previous prime is 1645503582407. The next prime is 1645503582421. The reversal of 1645503582420 is 242853055461.

1645503582420 is a `hidden beast` number, since 1 + 6 + 4 + 5 + 50 + 358 + 242 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645503582421) 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, 49710075 + ... + 49743165.

It is an arithmetic number, because the mean of its divisors is an integer number (34844585412).

Almost surely, 2^{1645503582420} is an apocalyptic number.

1645503582420 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 1645503582420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2508810149664).

1645503582420 is an abundant number, since it is smaller than the sum of its proper divisors (3372116716908).

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

1645503582420 is a wasteful number, since it uses less digits than its factorization.

1645503582420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34550 (or 34545 counting only the distinct ones).

The product of its (nonzero) digits is 1152000, while the sum is 45.

The spelling of 1645503582420 in words is "one trillion, six hundred forty-five billion, five hundred three million, five hundred eighty-two thousand, four hundred twenty".