81125356299 has 64 divisors (see below), whose sum is σ = 120836136960. Its totient is φ = 48096397440.

The previous prime is 81125356261. The next prime is 81125356309. The reversal of 81125356299 is 99265352118.

It is a happy number.

It is not a de Polignac number, because 81125356299 - 2¹⁹ = 81124832011 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81125356219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 39322942 + ... + 39325004.

It is an arithmetic number, because the mean of its divisors is an integer number (1888064640).

Almost surely, 2^81125356299 is an apocalyptic number.

81125356299 is a deficient number, since it is larger than the sum of its proper divisors (39710780661).

81125356299 is a wasteful number, since it uses less digits than its factorization.

81125356299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2432.

The product of its digits is 1166400, while the sum is 51.

The spelling of 81125356299 in words is "eighty-one billion, one hundred twenty-five million, three hundred fifty-six thousand, two hundred ninety-nine".