81606750 has 64 divisors (see below), whose sum is σ = 207634752. Its totient is φ = 21340800.

The previous prime is 81606739. The next prime is 81606781. The reversal of 81606750 is 5760618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38724 + ... + 40776.

It is an arithmetic number, because the mean of its divisors is an integer number (3244293).

Almost surely, 2^81606750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81606750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103817376).

81606750 is an abundant number, since it is smaller than the sum of its proper divisors (126028002).

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

81606750 is a wasteful number, since it uses less digits than its factorization.

81606750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2126 (or 2116 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 81606750 is about 9033.6454435626. The cubic root of 81606750 is about 433.7525364788.

The spelling of 81606750 in words is "eighty-one million, six hundred six thousand, seven hundred fifty".