1645356543520 has 24 divisors (see below), whose sum is σ = 3887154834444. Its totient is φ = 658142617344.

The previous prime is 1645356543431. The next prime is 1645356543533. The reversal of 1645356543520 is 253456535461.

It can be written as a sum of positive squares in 2 ways, for example, as 1638533122704 + 6823420816 = 1280052^2 + 82604^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5141739039 + ... + 5141739358.

Almost surely, 2^{1645356543520} is an apocalyptic number.

1645356543520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1645356543520 is an abundant number, since it is smaller than the sum of its proper divisors (2241798290924).

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

1645356543520 is a wasteful number, since it uses less digits than its factorization.

1645356543520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10283478412 (or 10283478404 counting only the distinct ones).

The product of its (nonzero) digits is 6480000, while the sum is 49.

The spelling of 1645356543520 in words is "one trillion, six hundred forty-five billion, three hundred fifty-six million, five hundred forty-three thousand, five hundred twenty".