17978253707 has 4 divisors (see below), whose sum is σ = 18598193520. Its totient is φ = 17358313896.

The previous prime is 17978253703. The next prime is 17978253721. The reversal of 17978253707 is 70735287971.

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

It is a cyclic number.

It is not a de Polignac number, because 17978253707 - 2² = 17978253703 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17978253703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 309969863 + ... + 309969920.

It is an arithmetic number, because the mean of its divisors is an integer number (4649548380).

Almost surely, 2^17978253707 is an apocalyptic number.

17978253707 is a deficient number, since it is larger than the sum of its proper divisors (619939813).

17978253707 is an equidigital number, since it uses as much as digits as its factorization.

17978253707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619939812.

The product of its (nonzero) digits is 5186160, while the sum is 56.

The spelling of 17978253707 in words is "seventeen billion, nine hundred seventy-eight million, two hundred fifty-three thousand, seven hundred seven".