617978 has 4 divisors (see below), whose sum is σ = 926970. Its totient is φ = 308988.

The previous prime is 617971. The next prime is 617983. The reversal of 617978 is 879716.

It is a happy number.

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., 597529 + 20449 = 773^2 + 143^2 .

It is not an unprimeable number, because it can be changed into a prime (617971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154493 + ... + 154496.

2⁶¹⁷⁹⁷⁸ is an apocalyptic number.

617978 is a deficient number, since it is larger than the sum of its proper divisors (308992).

617978 is a wasteful number, since it uses less digits than its factorization.

617978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308991.

The product of its digits is 21168, while the sum is 38.

The square root of 617978 is about 786.1157675559. The cubic root of 617978 is about 85.1773919310.

The spelling of 617978 in words is "six hundred seventeen thousand, nine hundred seventy-eight".