978195811 has 4 divisors (see below), whose sum is σ = 979038072. Its totient is φ = 977353552.

The previous prime is 978195809. The next prime is 978195853. The reversal of 978195811 is 118591879.

It is a happy number.

978195811 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 978195811 - 2¹ = 978195809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (978195311) 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, 419386 + ... + 421711.

It is an arithmetic number, because the mean of its divisors is an integer number (244759518).

Almost surely, 2^978195811 is an apocalyptic number.

978195811 is a deficient number, since it is larger than the sum of its proper divisors (842261).

978195811 is a wasteful number, since it uses less digits than its factorization.

978195811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842260.

The product of its digits is 181440, while the sum is 49.

The square root of 978195811 is about 31276.1220582092. The cubic root of 978195811 is about 992.6784629182.

The spelling of 978195811 in words is "nine hundred seventy-eight million, one hundred ninety-five thousand, eight hundred eleven".