79978887997 has 2 divisors, whose sum is σ = 79978887998. Its totient is φ = 79978887996.

The previous prime is 79978887953. The next prime is 79978888013.

79978887997 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54858539961 + 25120348036 = 234219^2 + 158494^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 79978887997 - 2¹¹ = 79978885949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79978887917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39989443998 + 39989443999.

It is an arithmetic number, because the mean of its divisors is an integer number (39989443999).

Almost surely, 2^79978887997 is an apocalyptic number.

It is an amenable number.

79978887997 is a deficient number, since it is larger than the sum of its proper divisors (1).

79978887997 is an equidigital number, since it uses as much as digits as its factorization.

79978887997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8065516032, while the sum is 88.

The spelling of 79978887997 in words is "seventy-nine billion, nine hundred seventy-eight million, eight hundred eighty-seven thousand, nine hundred ninety-seven".