1645515555645 has 32 divisors (see below), whose sum is σ = 3002135173632. Its totient is φ = 762447025152.

The previous prime is 1645515555581. The next prime is 1645515555647. The reversal of 1645515555645 is 5465555155461.

It is not a de Polignac number, because 1645515555645 - 2⁶ = 1645515555581 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645515555647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 248189077 + ... + 248195706.

It is an arithmetic number, because the mean of its divisors is an integer number (93816724176).

Almost surely, 2^{1645515555645} is an apocalyptic number.

1645515555645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1645515555645 is a deficient number, since it is larger than the sum of its proper divisors (1356619617987).

1645515555645 is a wasteful number, since it uses less digits than its factorization.

1645515555645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496384821.

The product of its digits is 45000000, while the sum is 57.

The spelling of 1645515555645 in words is "one trillion, six hundred forty-five billion, five hundred fifteen million, five hundred fifty-five thousand, six hundred forty-five".