1645817555683 has 32 divisors (see below), whose sum is σ = 1994548727808. Its totient is φ = 1327988649600.

The previous prime is 1645817555659. The next prime is 1645817555689. The reversal of 1645817555683 is 3865557185461.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1645817555683 - 2⁵ = 1645817555651 is a prime.

It is a Smith number, since the sum of its digits (64) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1645817555689) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38413413 + ... + 38456233.

It is an arithmetic number, because the mean of its divisors is an integer number (62329647744).

Almost surely, 2^{1645817555683} is an apocalyptic number.

1645817555683 is a deficient number, since it is larger than the sum of its proper divisors (348731172125).

1645817555683 is a wasteful number, since it uses less digits than its factorization.

1645817555683 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47683.

The product of its digits is 120960000, while the sum is 64.

The spelling of 1645817555683 in words is "one trillion, six hundred forty-five billion, eight hundred seventeen million, five hundred fifty-five thousand, six hundred eighty-three".