789449978 has 16 divisors (see below), whose sum is σ = 1262255400. Its totient is φ = 369010176.

The previous prime is 789449971. The next prime is 789449987. The reversal of 789449978 is 879944987.

It can be written as a sum of positive squares in 4 ways, for example, as 509991889 + 279458089 = 22583^2 + 16717^2 .

It is not an unprimeable number, because it can be changed into a prime (789449971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72851 + ... + 82982.

Almost surely, 2^789449978 is an apocalyptic number.

789449978 is a deficient number, since it is larger than the sum of its proper divisors (472805422).

789449978 is a wasteful number, since it uses less digits than its factorization.

789449978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156001.

The product of its digits is 36578304, while the sum is 65.

The square root of 789449978 is about 28097.1524891758. The cubic root of 789449978 is about 924.2189571557.

The spelling of 789449978 in words is "seven hundred eighty-nine million, four hundred forty-nine thousand, nine hundred seventy-eight".