79399654109561 has 2 divisors, whose sum is σ = 79399654109562. Its totient is φ = 79399654109560.

The previous prime is 79399654109557. The next prime is 79399654109591. The reversal of 79399654109561 is 16590145699397.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73010103714025 + 6389550395536 = 8544595^2 + 2527756^2 .

It is a cyclic number.

It is not a de Polignac number, because 79399654109561 - 2² = 79399654109557 is a prime.

It is a super-2 number, since 2×79399654109561² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (79399654109591) 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, 39699827054780 + 39699827054781.

It is an arithmetic number, because the mean of its divisors is an integer number (39699827054781).

Almost surely, 2^{79399654109561} is an apocalyptic number.

It is an amenable number.

79399654109561 is a deficient number, since it is larger than the sum of its proper divisors (1).

79399654109561 is an equidigital number, since it uses as much as digits as its factorization.

79399654109561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 496011600, while the sum is 74.

The spelling of 79399654109561 in words is "seventy-nine trillion, three hundred ninety-nine billion, six hundred fifty-four million, one hundred nine thousand, five hundred sixty-one".