1645217969745 has 16 divisors (see below), whose sum is σ = 3008398573440. Its totient is φ = 752099643264.

The previous prime is 1645217969713. The next prime is 1645217969767. The reversal of 1645217969745 is 5479697125461.

It is not a de Polignac number, because 1645217969745 - 2⁵ = 1645217969713 is a prime.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 7834371180 + ... + 7834371389.

It is an arithmetic number, because the mean of its divisors is an integer number (188024910840).

Almost surely, 2^{1645217969745} is an apocalyptic number.

1645217969745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1645217969745 is a deficient number, since it is larger than the sum of its proper divisors (1363180603695).

1645217969745 is a wasteful number, since it uses less digits than its factorization.

1645217969745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15668742584.

The product of its digits is 114307200, while the sum is 66.

The spelling of 1645217969745 in words is "one trillion, six hundred forty-five billion, two hundred seventeen million, nine hundred sixty-nine thousand, seven hundred forty-five".