79811609 has 4 divisors (see below), whose sum is σ = 84012240. Its totient is φ = 75610980.

The previous prime is 79811591. The next prime is 79811657. The reversal of 79811609 is 90611897.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 79811609 - 2⁸ = 79811353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79811659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2100287 + ... + 2100324.

It is an arithmetic number, because the mean of its divisors is an integer number (21003060).

Almost surely, 2^79811609 is an apocalyptic number.

It is an amenable number.

79811609 is a deficient number, since it is larger than the sum of its proper divisors (4200631).

79811609 is a wasteful number, since it uses less digits than its factorization.

79811609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4200630.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 79811609 is about 8933.7343255774. The cubic root of 79811609 is about 430.5484420725.

The spelling of 79811609 in words is "seventy-nine million, eight hundred eleven thousand, six hundred nine".