1217638673 has 4 divisors (see below), whose sum is σ = 1228809780. Its totient is φ = 1206467568.

The previous prime is 1217638633. The next prime is 1217638703. The reversal of 1217638673 is 3768367121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1024512064 + 193126609 = 32008^2 + 13897^2 .

It is a cyclic number.

It is not a de Polignac number, because 1217638673 - 2⁸ = 1217638417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1217638603) 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, 5585390 + ... + 5585607.

It is an arithmetic number, because the mean of its divisors is an integer number (307202445).

Almost surely, 2^1217638673 is an apocalyptic number.

It is an amenable number.

1217638673 is a deficient number, since it is larger than the sum of its proper divisors (11171107).

1217638673 is a wasteful number, since it uses less digits than its factorization.

1217638673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11171106.

The product of its digits is 254016, while the sum is 44.

The square root of 1217638673 is about 34894.6797234192. The cubic root of 1217638673 is about 1067.8399001714.

The spelling of 1217638673 in words is "one billion, two hundred seventeen million, six hundred thirty-eight thousand, six hundred seventy-three".