81895508001216 has 840 divisors, whose sum is σ = 304269664794480. Its totient is φ = 21588319936512.

The previous prime is 81895508001211. The next prime is 81895508001247. The reversal of 81895508001216 is 61210080559818.

81895508001216 is a `hidden beast` number, since 8 + 1 + 8 + 9 + 5 + 508 + 0 + 0 + 121 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81895508001211) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 8694708955 + ... + 8694718373.

It is an arithmetic number, because the mean of its divisors is an integer number (362225791422).

Almost surely, 2^{81895508001216} 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 81895508001216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152134832397240).

81895508001216 is an abundant number, since it is smaller than the sum of its proper divisors (222374156793264).

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

81895508001216 is a wasteful number, since it uses less digits than its factorization.

81895508001216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12103 (or 12077 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 54.

The spelling of 81895508001216 in words is "eighty-one trillion, eight hundred ninety-five billion, five hundred eight million, one thousand, two hundred sixteen".