81519264000 has 288 divisors, whose sum is σ = 300854561280. Its totient is φ = 21738240000.

The previous prime is 81519263977. The next prime is 81519264007. The reversal of 81519264000 is 46291518.

81519264000 is a `hidden beast` number, since 8 + 1 + 5 + 1 + 9 + 2 + 640 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is not an unprimeable number, because it can be changed into a prime (81519264007) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 816825 + ... + 911175.

Almost surely, 2^81519264000 is an apocalyptic number.

81519264000 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81519264000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150427280640).

81519264000 is an abundant number, since it is smaller than the sum of its proper divisors (219335297280).

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

81519264000 is an equidigital number, since it uses as much as digits as its factorization.

81519264000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94391 (or 94361 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 81519264000 in words is "eighty-one billion, five hundred nineteen million, two hundred sixty-four thousand".