727978 has 4 divisors (see below), whose sum is σ = 1091970. Its totient is φ = 363988.

The previous prime is 727949. The next prime is 727981. The reversal of 727978 is 879727.

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

It can be written as a sum of positive squares in only one way, i.e., 651249 + 76729 = 807^2 + 277^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 727978.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 181993 + ... + 181996.

2⁷²⁷⁹⁷⁸ is an apocalyptic number.

727978 is a deficient number, since it is larger than the sum of its proper divisors (363992).

727978 is a wasteful number, since it uses less digits than its factorization.

727978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363991.

The product of its digits is 49392, while the sum is 40.

The square root of 727978 is about 853.2162680118. The cubic root of 727978 is about 89.9579227177.

The spelling of 727978 in words is "seven hundred twenty-seven thousand, nine hundred seventy-eight".