81500708 has 6 divisors (see below), whose sum is σ = 142626246. Its totient is φ = 40750352.

The previous prime is 81500689. The next prime is 81500711. The reversal of 81500708 is 80700518.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 57274624 + 24226084 = 7568^2 + 4922^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10187585 + ... + 10187592.

It is an arithmetic number, because the mean of its divisors is an integer number (23771041).

Almost surely, 2^81500708 is an apocalyptic number.

It is an amenable number.

81500708 is a deficient number, since it is larger than the sum of its proper divisors (61125538).

81500708 is a wasteful number, since it uses less digits than its factorization.

81500708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20375181 (or 20375179 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 29.

The square root of 81500708 is about 9027.7742550420. The cubic root of 81500708 is about 433.5645784824.

The spelling of 81500708 in words is "eighty-one million, five hundred thousand, seven hundred eight".