81510425468640 has 1152 divisors, whose sum is σ = 339890466988800. Its totient is φ = 17363814580224.

The previous prime is 81510425468627. The next prime is 81510425468713. The reversal of 81510425468640 is 4686452401518.

81510425468640 is a `hidden beast` number, since 8 + 1 + 5 + 10 + 4 + 2 + 546 + 86 + 4 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

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 191 ways as a sum of consecutive naturals, for example, 8604494944 + ... + 8604504416.

It is an arithmetic number, because the mean of its divisors is an integer number (295043808150).

Almost surely, 2^{81510425468640} is an apocalyptic number.

81510425468640 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 81510425468640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169945233494400).

81510425468640 is an abundant number, since it is smaller than the sum of its proper divisors (258380041520160).

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

81510425468640 is a wasteful number, since it uses less digits than its factorization.

81510425468640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10004 (or 9993 counting only the distinct ones).

The product of its (nonzero) digits is 7372800, while the sum is 54.

The spelling of 81510425468640 in words is "eighty-one trillion, five hundred ten billion, four hundred twenty-five million, four hundred sixty-eight thousand, six hundred forty".