81549725423 has 2 divisors, whose sum is σ = 81549725424. Its totient is φ = 81549725422.

The previous prime is 81549725417. The next prime is 81549725429. The reversal of 81549725423 is 32452794518.

It is a balanced prime because it is at equal distance from previous prime (81549725417) and next prime (81549725429).

It is a cyclic number.

It is not a de Polignac number, because 81549725423 - 2²⁴ = 81532948207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81549725429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40774862711 + 40774862712.

It is an arithmetic number, because the mean of its divisors is an integer number (40774862712).

Almost surely, 2^81549725423 is an apocalyptic number.

81549725423 is a deficient number, since it is larger than the sum of its proper divisors (1).

81549725423 is an equidigital number, since it uses as much as digits as its factorization.

81549725423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2419200, while the sum is 50.

The spelling of 81549725423 in words is "eighty-one billion, five hundred forty-nine million, seven hundred twenty-five thousand, four hundred twenty-three".