81577344377518 has 16 divisors (see below), whose sum is σ = 140515999885440. Its totient is φ = 35128999971000.

The previous prime is 81577344377489. The next prime is 81577344377519.

81577344377518 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 (81577344377519) 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, 97580555058 + ... + 97580555893.

It is an arithmetic number, because the mean of its divisors is an integer number (8782249992840).

Almost surely, 2^{81577344377518} is an apocalyptic number.

81577344377518 is a deficient number, since it is larger than the sum of its proper divisors (58938655507922).

81577344377518 is a wasteful number, since it uses less digits than its factorization.

81577344377518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195161110983.

The product of its digits is 553190400, while the sum is 70.

The spelling of 81577344377518 in words is "eighty-one trillion, five hundred seventy-seven billion, three hundred forty-four million, three hundred seventy-seven thousand, five hundred eighteen".