978854809 has 4 divisors (see below), whose sum is σ = 979822116. Its totient is φ = 977887504.

The previous prime is 978854803. The next prime is 978854813. The reversal of 978854809 is 908458879.

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

It can be written as a sum of positive squares in 2 ways, for example, as 509179225 + 469675584 = 22565^2 + 21672^2 .

It is a cyclic number.

It is not a de Polignac number, because 978854809 - 2¹¹ = 978852761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (978854803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 482134 + ... + 484159.

It is an arithmetic number, because the mean of its divisors is an integer number (244955529).

Almost surely, 2^978854809 is an apocalyptic number.

It is an amenable number.

978854809 is a deficient number, since it is larger than the sum of its proper divisors (967307).

978854809 is a wasteful number, since it uses less digits than its factorization.

978854809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 967306.

The product of its (nonzero) digits is 5806080, while the sum is 58.

The square root of 978854809 is about 31286.6554460524. The cubic root of 978854809 is about 992.9013311369.

The spelling of 978854809 in words is "nine hundred seventy-eight million, eight hundred fifty-four thousand, eight hundred nine".