1663690173 has 4 divisors (see below), whose sum is σ = 2218253568. Its totient is φ = 1109126780.

The previous prime is 1663690157. The next prime is 1663690177. The reversal of 1663690173 is 3710963661.

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 1663690173 - 2⁴ = 1663690157 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663690177) 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, 277281693 + ... + 277281698.

It is an arithmetic number, because the mean of its divisors is an integer number (554563392).

Almost surely, 2^1663690173 is an apocalyptic number.

It is an amenable number.

1663690173 is a deficient number, since it is larger than the sum of its proper divisors (554563395).

1663690173 is an equidigital number, since it uses as much as digits as its factorization.

1663690173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554563394.

The product of its (nonzero) digits is 122472, while the sum is 42.

The square root of 1663690173 is about 40788.3583023392. The cubic root of 1663690173 is about 1184.9248762218.

The spelling of 1663690173 in words is "one billion, six hundred sixty-three million, six hundred ninety thousand, one hundred seventy-three".