81315481554825 has 192 divisors, whose sum is σ = 160712793722880. Its totient is φ = 35471316418560.

The previous prime is 81315481554823. The next prime is 81315481554851. The reversal of 81315481554825 is 52845518451318.

81315481554825 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 81315481554825 - 2¹ = 81315481554823 is a prime.

It is a super-2 number, since 2×81315481554825² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81315481554823) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 10939789309 + ... + 10939796741.

It is an arithmetic number, because the mean of its divisors is an integer number (837045800640).

Almost surely, 2^{81315481554825} is an apocalyptic number.

It is an amenable number.

81315481554825 is a deficient number, since it is larger than the sum of its proper divisors (79397312168055).

81315481554825 is a wasteful number, since it uses less digits than its factorization.

81315481554825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9528 (or 9523 counting only the distinct ones).

The product of its digits is 30720000, while the sum is 60.

The spelling of 81315481554825 in words is "eighty-one trillion, three hundred fifteen billion, four hundred eighty-one million, five hundred fifty-four thousand, eight hundred twenty-five".