81201315456 has 512 divisors, whose sum is σ = 260876505600. Its totient is φ = 25082265600.

The previous prime is 81201315331. The next prime is 81201315457. The reversal of 81201315456 is 65451310218.

81201315456 is a `hidden beast` number, since 81 + 2 + 0 + 1 + 31 + 545 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81201315456.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81201315457) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 537756981 + ... + 537757131.

It is an arithmetic number, because the mean of its divisors is an integer number (509524425).

Almost surely, 2^81201315456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81201315456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130438252800).

81201315456 is an abundant number, since it is smaller than the sum of its proper divisors (179675190144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81201315456 is a wasteful number, since it uses less digits than its factorization.

81201315456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The spelling of 81201315456 in words is "eighty-one billion, two hundred one million, three hundred fifteen thousand, four hundred fifty-six".