81089507425 has 12 divisors (see below), whose sum is σ = 106465753836. Its totient is φ = 61055628800.

The previous prime is 81089507393. The next prime is 81089507449. The reversal of 81089507425 is 52470598018.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 9477606609 + 71611900816 = 97353^2 + 267604^2 .

It is not a de Polignac number, because 81089507425 - 2⁵ = 81089507393 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95398996 + ... + 95399845.

It is an arithmetic number, because the mean of its divisors is an integer number (8872146153).

Almost surely, 2^81089507425 is an apocalyptic number.

81089507425 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81089507425 is a deficient number, since it is larger than the sum of its proper divisors (25376246411).

81089507425 is a wasteful number, since it uses less digits than its factorization.

81089507425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190798868 (or 190798863 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 49.

The spelling of 81089507425 in words is "eighty-one billion, eighty-nine million, five hundred seven thousand, four hundred twenty-five".