81515103 has 4 divisors (see below), whose sum is σ = 108686808. Its totient is φ = 54343400.

The previous prime is 81515053. The next prime is 81515129. The reversal of 81515103 is 30151518.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81515103 - 2¹⁰ = 81514079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81515173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13585848 + ... + 13585853.

It is an arithmetic number, because the mean of its divisors is an integer number (27171702).

Almost surely, 2^81515103 is an apocalyptic number.

81515103 is a deficient number, since it is larger than the sum of its proper divisors (27171705).

81515103 is a wasteful number, since it uses less digits than its factorization.

81515103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27171704.

The product of its (nonzero) digits is 600, while the sum is 24.

The square root of 81515103 is about 9028.5714816908. The cubic root of 81515103 is about 433.5901029834.

It can be divided in two parts, 81515 and 103, that added together give a palindrome (81618).

The spelling of 81515103 in words is "eighty-one million, five hundred fifteen thousand, one hundred three".