81242366499 has 20 divisors (see below), whose sum is σ = 138699490864. Its totient is φ = 46424209104.

The previous prime is 81242366459. The next prime is 81242366501. The reversal of 81242366499 is 99466324218.

81242366499 is a `hidden beast` number, since 8 + 124 + 23 + 6 + 6 + 499 = 666.

It is not a de Polignac number, because 81242366499 - 2¹² = 81242362403 is a prime.

It is a super-2 number, since 2×81242366499² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81242366449) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 71641732 + ... + 71642865.

Almost surely, 2^81242366499 is an apocalyptic number.

81242366499 is a deficient number, since it is larger than the sum of its proper divisors (57457124365).

81242366499 is a wasteful number, since it uses less digits than its factorization.

81242366499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143284616 (or 143284607 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 54.

The spelling of 81242366499 in words is "eighty-one billion, two hundred forty-two million, three hundred sixty-six thousand, four hundred ninety-nine".