81531466413518 has 16 divisors (see below), whose sum is σ = 134736068712240. Its totient is φ = 36692829168000.

The previous prime is 81531466413493. The next prime is 81531466413563.

81531466413518 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×81531466413518² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18346412363 + ... + 18346416806.

It is an arithmetic number, because the mean of its divisors is an integer number (8421004294515).

Almost surely, 2^{81531466413518} is an apocalyptic number.

81531466413518 is a deficient number, since it is larger than the sum of its proper divisors (53204602298722).

81531466413518 is a wasteful number, since it uses less digits than its factorization.

81531466413518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36692829283.

The product of its digits is 8294400, while the sum is 56.

The spelling of 81531466413518 in words is "eighty-one trillion, five hundred thirty-one billion, four hundred sixty-six million, four hundred thirteen thousand, five hundred eighteen".