81503113 has 8 divisors (see below), whose sum is σ = 82889768. Its totient is φ = 80123904.

The previous prime is 81503057. The next prime is 81503153. The reversal of 81503113 is 31130518.

It can be written as a sum of positive squares in 4 ways, for example, as 23011209 + 58491904 = 4797^2 + 7648^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81503113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81503153) 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, 22945 + ... + 26257.

It is an arithmetic number, because the mean of its divisors is an integer number (10361221).

Almost surely, 2^81503113 is an apocalyptic number.

It is an amenable number.

81503113 is a deficient number, since it is larger than the sum of its proper divisors (1386655).

81503113 is a wasteful number, since it uses less digits than its factorization.

81503113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3723.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 81503113 is about 9027.9074541114. The cubic root of 81503113 is about 433.5688431184.

The spelling of 81503113 in words is "eighty-one million, five hundred three thousand, one hundred thirteen".