81394284025 has 12 divisors (see below), whose sum is σ = 102583486444. Its totient is φ = 64047960000.

The previous prime is 81394284007. The next prime is 81394284029. The reversal of 81394284025 is 52048249318.

It can be written as a sum of positive squares in 6 ways, for example, as 3065947641 + 78328336384 = 55371^2 + 279872^2 .

It is not a de Polignac number, because 81394284025 - 2⁹ = 81394283513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81394284029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26685126 + ... + 26688175.

Almost surely, 2^81394284025 is an apocalyptic number.

It is an amenable number.

81394284025 is a deficient number, since it is larger than the sum of its proper divisors (21189202419).

81394284025 is a wasteful number, since it uses less digits than its factorization.

81394284025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53373372 (or 53373367 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 46.

The spelling of 81394284025 in words is "eighty-one billion, three hundred ninety-four million, two hundred eighty-four thousand, twenty-five".