978491789 has 24 divisors (see below), whose sum is σ = 1118949216. Its totient is φ = 854330400.

The previous prime is 978491753. The next prime is 978491803. The reversal of 978491789 is 987194879.

978491789 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-978491789 is a prime.

It is a super-2 number, since 2×978491789² = 1914892362280841042, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (978431789) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 315842 + ... + 318924.

It is an arithmetic number, because the mean of its divisors is an integer number (46622884).

Almost surely, 2^978491789 is an apocalyptic number.

It is an amenable number.

978491789 is a deficient number, since it is larger than the sum of its proper divisors (140457427).

978491789 is a wasteful number, since it uses less digits than its factorization.

978491789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3209 (or 3198 counting only the distinct ones).

The product of its digits is 9144576, while the sum is 62.

The square root of 978491789 is about 31280.8533930902. The cubic root of 978491789 is about 992.7785728534.

The spelling of 978491789 in words is "nine hundred seventy-eight million, four hundred ninety-one thousand, seven hundred eighty-nine".