79839457409 has 2 divisors, whose sum is σ = 79839457410. Its totient is φ = 79839457408.

The previous prime is 79839457403. The next prime is 79839457427. The reversal of 79839457409 is 90475493897.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50451898225 + 29387559184 = 224615^2 + 171428^2 .

It is a cyclic number.

It is not a de Polignac number, because 79839457409 - 2⁴ = 79839457393 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (79839457403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39919728704 + 39919728705.

It is an arithmetic number, because the mean of its divisors is an integer number (39919728705).

Almost surely, 2^79839457409 is an apocalyptic number.

It is an amenable number.

79839457409 is a deficient number, since it is larger than the sum of its proper divisors (1).

79839457409 is an equidigital number, since it uses as much as digits as its factorization.

79839457409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 68584320, while the sum is 65.

The spelling of 79839457409 in words is "seventy-nine billion, eight hundred thirty-nine million, four hundred fifty-seven thousand, four hundred nine".