809443979 has 8 divisors (see below), whose sum is σ = 819653040. Its totient is φ = 799284096.

The previous prime is 809443963. The next prime is 809443993. The reversal of 809443979 is 979344908.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 809443979 - 2⁴ = 809443963 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 809443979.

It is not an unprimeable number, because it can be changed into a prime (809443939) 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, 21407 + ... + 45575.

It is an arithmetic number, because the mean of its divisors is an integer number (102456630).

Almost surely, 2^809443979 is an apocalyptic number.

809443979 is a deficient number, since it is larger than the sum of its proper divisors (10209061).

809443979 is a wasteful number, since it uses less digits than its factorization.

809443979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24589.

The product of its (nonzero) digits is 1959552, while the sum is 53.

The square root of 809443979 is about 28450.7289713287. The cubic root of 809443979 is about 931.9564083297.

The spelling of 809443979 in words is "eight hundred nine million, four hundred forty-three thousand, nine hundred seventy-nine".