1665653636213 has 4 divisors (see below), whose sum is σ = 1903604155680. Its totient is φ = 1427703116748.

The previous prime is 1665653636189. The next prime is 1665653636267. The reversal of 1665653636213 is 3126363565661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1665653636213 - 2⁸ = 1665653635957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665653636113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118975259723 + ... + 118975259736.

It is an arithmetic number, because the mean of its divisors is an integer number (475901038920).

Almost surely, 2^{1665653636213} is an apocalyptic number.

It is an amenable number.

1665653636213 is a deficient number, since it is larger than the sum of its proper divisors (237950519467).

1665653636213 is an equidigital number, since it uses as much as digits as its factorization.

1665653636213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237950519466.

The product of its digits is 10497600, while the sum is 53.

The spelling of 1665653636213 in words is "one trillion, six hundred sixty-five billion, six hundred fifty-three million, six hundred thirty-six thousand, two hundred thirteen".