78999357457 has 2 divisors, whose sum is σ = 78999357458. Its totient is φ = 78999357456.

The previous prime is 78999357443. The next prime is 78999357473. The reversal of 78999357457 is 75475399987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46297698561 + 32701658896 = 215169^2 + 180836^2 .

It is a cyclic number.

It is not a de Polignac number, because 78999357457 - 2⁷ = 78999357329 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78999357457.

It is not a weakly prime, because it can be changed into another prime (78999357407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39499678728 + 39499678729.

It is an arithmetic number, because the mean of its divisors is an integer number (39499678729).

Almost surely, 2^78999357457 is an apocalyptic number.

It is an amenable number.

78999357457 is a deficient number, since it is larger than the sum of its proper divisors (1).

78999357457 is an equidigital number, since it uses as much as digits as its factorization.

78999357457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 600112800, while the sum is 73.

The spelling of 78999357457 in words is "seventy-eight billion, nine hundred ninety-nine million, three hundred fifty-seven thousand, four hundred fifty-seven".