81500073 has 8 divisors (see below), whose sum is σ = 110288928. Its totient is φ = 53522304.

The previous prime is 81499997. The next prime is 81500077. The reversal of 81500073 is 37000518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81500073 - 2¹³ = 81491881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81500077) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202536 + ... + 202937.

It is an arithmetic number, because the mean of its divisors is an integer number (13786116).

Almost surely, 2^81500073 is an apocalyptic number.

It is an amenable number.

81500073 is a deficient number, since it is larger than the sum of its proper divisors (28788855).

81500073 is a wasteful number, since it uses less digits than its factorization.

81500073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405543.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 81500073 is about 9027.7390857291. The cubic root of 81500073 is about 433.5634524627.

The spelling of 81500073 in words is "eighty-one million, five hundred thousand, seventy-three".