81523232518 has 32 divisors (see below), whose sum is σ = 151994606400. Its totient is φ = 31931625600.

The previous prime is 81523232513. The next prime is 81523232551.

81523232518 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81523232513) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2199093 + ... + 2235856.

It is an arithmetic number, because the mean of its divisors is an integer number (4749831450).

Almost surely, 2^81523232518 is an apocalyptic number.

81523232518 is a deficient number, since it is larger than the sum of its proper divisors (70471373882).

81523232518 is a wasteful number, since it uses less digits than its factorization.

81523232518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4435072.

The product of its digits is 115200, while the sum is 40.

The spelling of 81523232518 in words is "eighty-one billion, five hundred twenty-three million, two hundred thirty-two thousand, five hundred eighteen".