81281260725 has 48 divisors (see below), whose sum is σ = 153609930240. Its totient is φ = 37150603200.

The previous prime is 81281260703. The next prime is 81281260763. The reversal of 81281260725 is 52706218218.

It is not a de Polignac number, because 81281260725 - 2⁸ = 81281260469 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4221370 + ... + 4240580.

It is an arithmetic number, because the mean of its divisors is an integer number (3200206880).

Almost surely, 2^81281260725 is an apocalyptic number.

It is an amenable number.

81281260725 is a deficient number, since it is larger than the sum of its proper divisors (72328669515).

81281260725 is a wasteful number, since it uses less digits than its factorization.

81281260725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27290 (or 27285 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 42.

The spelling of 81281260725 in words is "eighty-one billion, two hundred eighty-one million, two hundred sixty thousand, seven hundred twenty-five".