81125598803 has 4 divisors (see below), whose sum is σ = 81137569248. Its totient is φ = 81113628360.

The previous prime is 81125598779. The next prime is 81125598857. The reversal of 81125598803 is 30889552118.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30889552118 = 2 ⋅15444776059.

It is a cyclic number.

It is not a de Polignac number, because 81125598803 - 2²² = 81121404499 is a prime.

It is a super-2 number, since 2×81125598803² (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 (81145598803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5975051 + ... + 5988612.

It is an arithmetic number, because the mean of its divisors is an integer number (20284392312).

Almost surely, 2^81125598803 is an apocalyptic number.

81125598803 is a deficient number, since it is larger than the sum of its proper divisors (11970445).

81125598803 is a wasteful number, since it uses less digits than its factorization.

81125598803 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11970444.

The product of its (nonzero) digits is 691200, while the sum is 50.

The spelling of 81125598803 in words is "eighty-one billion, one hundred twenty-five million, five hundred ninety-eight thousand, eight hundred three".