18655961573 has 12 divisors (see below), whose sum is σ = 19193634180. Its totient is φ = 18132837120.

The previous prime is 18655961563. The next prime is 18655961581. The reversal of 18655961573 is 37516955681.

It can be written as a sum of positive squares in 6 ways, for example, as 11928353089 + 6727608484 = 109217^2 + 82022^2 .

It is not a de Polignac number, because 18655961573 - 2⁴ = 18655961557 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 (18655961563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 431561 + ... + 472817.

It is an arithmetic number, because the mean of its divisors is an integer number (1599469515).

Almost surely, 2^18655961573 is an apocalyptic number.

It is an amenable number.

18655961573 is a deficient number, since it is larger than the sum of its proper divisors (537672607).

18655961573 is an equidigital number, since it uses as much as digits as its factorization.

18655961573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41608 (or 41567 counting only the distinct ones).

The product of its digits is 6804000, while the sum is 56.

The spelling of 18655961573 in words is "eighteen billion, six hundred fifty-five million, nine hundred sixty-one thousand, five hundred seventy-three".