1645604444013 has 64 divisors (see below), whose sum is σ = 2364065071104. Its totient is φ = 1016318016000.

The previous prime is 1645604443999. The next prime is 1645604444023. The reversal of 1645604444013 is 3104444065461.

It is a happy number.

It is not a de Polignac number, because 1645604444013 - 2⁸ = 1645604443757 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645604444023) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 68534856 + ... + 68558862.

It is an arithmetic number, because the mean of its divisors is an integer number (36938516736).

Almost surely, 2^{1645604444013} is an apocalyptic number.

It is an amenable number.

1645604444013 is a deficient number, since it is larger than the sum of its proper divisors (718460627091).

1645604444013 is a wasteful number, since it uses less digits than its factorization.

1645604444013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24426.

The product of its (nonzero) digits is 552960, while the sum is 42.

The spelling of 1645604444013 in words is "one trillion, six hundred forty-five billion, six hundred four million, four hundred forty-four thousand, thirteen".