81425145523 has 2 divisors, whose sum is σ = 81425145524. Its totient is φ = 81425145522.

The previous prime is 81425145469. The next prime is 81425145611. The reversal of 81425145523 is 32554152418.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81425145523 is a prime.

It is not a weakly prime, because it can be changed into another prime (81425149523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40712572761 + 40712572762.

It is an arithmetic number, because the mean of its divisors is an integer number (40712572762).

Almost surely, 2^81425145523 is an apocalyptic number.

81425145523 is a deficient number, since it is larger than the sum of its proper divisors (1).

81425145523 is an equidigital number, since it uses as much as digits as its factorization.

81425145523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192000, while the sum is 40.

The spelling of 81425145523 in words is "eighty-one billion, four hundred twenty-five million, one hundred forty-five thousand, five hundred twenty-three".