81631003069440 has 1056 divisors, whose sum is σ = 310394014834176. Its totient is φ = 19672329093120.

The previous prime is 81631003069411. The next prime is 81631003069459. The reversal of 81631003069440 is 4496030013618.

81631003069440 is a `hidden beast` number, since 8 + 1 + 631 + 0 + 0 + 3 + 0 + 6 + 9 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1056).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 90001105467 + ... + 90001106373.

Almost surely, 2^{81631003069440} is an apocalyptic number.

81631003069440 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 81631003069440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155197007417088).

81631003069440 is an abundant number, since it is smaller than the sum of its proper divisors (228763011764736).

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

81631003069440 is a wasteful number, since it uses less digits than its factorization.

81631003069440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1805 (or 1784 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 81631003069440 in words is "eighty-one trillion, six hundred thirty-one billion, three million, sixty-nine thousand, four hundred forty".