1665663355653 has 16 divisors (see below), whose sum is σ = 2422814016000. Its totient is φ = 1009480045680.

The previous prime is 1665663355649. The next prime is 1665663355717. The reversal of 1665663355653 is 3565533665661.

It is not a de Polignac number, because 1665663355653 - 2² = 1665663355649 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665663355253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2731398 + ... + 3285096.

It is an arithmetic number, because the mean of its divisors is an integer number (151425876000).

Almost surely, 2^{1665663355653} is an apocalyptic number.

It is an amenable number.

1665663355653 is a deficient number, since it is larger than the sum of its proper divisors (757150660347).

1665663355653 is a wasteful number, since it uses less digits than its factorization.

1665663355653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644872.

The product of its digits is 131220000, while the sum is 60.

The spelling of 1665663355653 in words is "one trillion, six hundred sixty-five billion, six hundred sixty-three million, three hundred fifty-five thousand, six hundred fifty-three".