978827809 has 12 divisors (see below), whose sum is σ = 1012358988. Its totient is φ = 946319360.

The previous prime is 978827779. The next prime is 978827827. The reversal of 978827809 is 908728879.

It can be written as a sum of positive squares in 6 ways, for example, as 526840209 + 451987600 = 22953^2 + 21260^2 .

It is a de Polignac number, because none of the positive numbers 2^k-978827809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (978827209) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 187377 + ... + 192529.

It is an arithmetic number, because the mean of its divisors is an integer number (84363249).

Almost surely, 2^978827809 is an apocalyptic number.

It is an amenable number.

978827809 is a deficient number, since it is larger than the sum of its proper divisors (33531179).

978827809 is a wasteful number, since it uses less digits than its factorization.

978827809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5348 (or 5307 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 58.

The square root of 978827809 is about 31286.2239492081. The cubic root of 978827809 is about 992.8922019034.

The spelling of 978827809 in words is "nine hundred seventy-eight million, eight hundred twenty-seven thousand, eight hundred nine".