81285277804025 has 6 divisors (see below), whose sum is σ = 100793744477022. Its totient is φ = 65028222243200.

The previous prime is 81285277803979. The next prime is 81285277804091. The reversal of 81285277804025 is 52040877258218.

It can be written as a sum of positive squares in 3 ways, for example, as 5514851050384 + 75770426753641 = 2348372^2 + 8704621^2 .

It is not a de Polignac number, because 81285277804025 - 2¹⁰ = 81285277803001 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1625705556056 + ... + 1625705556105.

It is an arithmetic number, because the mean of its divisors is an integer number (16798957412837).

Almost surely, 2^{81285277804025} is an apocalyptic number.

It is an amenable number.

81285277804025 is a deficient number, since it is larger than the sum of its proper divisors (19508466672997).

81285277804025 is a wasteful number, since it uses less digits than its factorization.

81285277804025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3251411112171 (or 3251411112166 counting only the distinct ones).

The product of its (nonzero) digits is 20070400, while the sum is 59.

The spelling of 81285277804025 in words is "eighty-one trillion, two hundred eighty-five billion, two hundred seventy-seven million, eight hundred four thousand, twenty-five".