78561005641723 has 12 divisors (see below), whose sum is σ = 90450999197208. Its totient is φ = 67660196243040.

The previous prime is 78561005641717. The next prime is 78561005641771. The reversal of 78561005641723 is 32714650016587.

It is not a de Polignac number, because 78561005641723 - 2¹³ = 78561005633531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78561005641823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9891837586 + ... + 9891845527.

It is an arithmetic number, because the mean of its divisors is an integer number (7537583266434).

Almost surely, 2^{78561005641723} is an apocalyptic number.

78561005641723 is a deficient number, since it is larger than the sum of its proper divisors (11889993555485).

78561005641723 is a wasteful number, since it uses less digits than its factorization.

78561005641723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19783683162 (or 19783683143 counting only the distinct ones).

The product of its (nonzero) digits is 8467200, while the sum is 55.

The spelling of 78561005641723 in words is "seventy-eight trillion, five hundred sixty-one billion, five million, six hundred forty-one thousand, seven hundred twenty-three".