81734463720 has 1536 divisors, whose sum is σ = 371165760000. Its totient is φ = 15895885824.

The previous prime is 81734463641. The next prime is 81734463731. The reversal of 81734463720 is 2736443718.

81734463720 is a `hidden beast` number, since 8 + 1 + 7 + 3 + 4 + 4 + 637 + 2 + 0 = 666.

It is a super-3 number, since 3×81734463720³ (a number of 34 digits) contains 333 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 2209039542 + ... + 2209039578.

It is an arithmetic number, because the mean of its divisors is an integer number (241644375).

Almost surely, 2^81734463720 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 81734463720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (185582880000).

81734463720 is an abundant number, since it is smaller than the sum of its proper divisors (289431296280).

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

81734463720 is a wasteful number, since it uses less digits than its factorization.

81734463720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 45.

The spelling of 81734463720 in words is "eighty-one billion, seven hundred thirty-four million, four hundred sixty-three thousand, seven hundred twenty".