78754507861 has 2 divisors, whose sum is σ = 78754507862. Its totient is φ = 78754507860.

The previous prime is 78754507849. The next prime is 78754507967. The reversal of 78754507861 is 16870545787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61222099761 + 17532408100 = 247431^2 + 132410^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78754507861 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78754507796 and 78754507805.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78754507831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39377253930 + 39377253931.

It is an arithmetic number, because the mean of its divisors is an integer number (39377253931).

Almost surely, 2^78754507861 is an apocalyptic number.

It is an amenable number.

78754507861 is a deficient number, since it is larger than the sum of its proper divisors (1).

78754507861 is an equidigital number, since it uses as much as digits as its factorization.

78754507861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13171200, while the sum is 58.

The spelling of 78754507861 in words is "seventy-eight billion, seven hundred fifty-four million, five hundred seven thousand, eight hundred sixty-one".