81158448765 has 32 divisors (see below), whose sum is σ = 130300047360. Its totient is φ = 43135855616.

The previous prime is 81158448751. The next prime is 81158448779. The reversal of 81158448765 is 56784485118.

It is an interprime number because it is at equal distance from previous prime (81158448751) and next prime (81158448779).

It is a cyclic number.

It is not a de Polignac number, because 81158448765 - 2¹¹ = 81158446717 is a prime.

It is a super-2 number, since 2×81158448765² (a number of 23 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 31 ways as a sum of consecutive naturals, for example, 7882741 + ... + 7893029.

It is an arithmetic number, because the mean of its divisors is an integer number (4071876480).

Almost surely, 2^81158448765 is an apocalyptic number.

It is an amenable number.

81158448765 is a deficient number, since it is larger than the sum of its proper divisors (49141598595).

81158448765 is a wasteful number, since it uses less digits than its factorization.

81158448765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12053.

The product of its digits is 8601600, while the sum is 57.

The spelling of 81158448765 in words is "eighty-one billion, one hundred fifty-eight million, four hundred forty-eight thousand, seven hundred sixty-five".