81336251049 has 8 divisors (see below), whose sum is σ = 108452580480. Its totient is φ = 54222044496.

The previous prime is 81336251027. The next prime is 81336251057. The reversal of 81336251049 is 94015263318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81336251049 - 2¹⁹ = 81335726761 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81336251049.

It is not an unprimeable number, because it can be changed into a prime (81336251449) 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, 439057 + ... + 596190.

It is an arithmetic number, because the mean of its divisors is an integer number (13556572560).

Almost surely, 2^81336251049 is an apocalyptic number.

It is an amenable number.

81336251049 is a deficient number, since it is larger than the sum of its proper divisors (27116329431).

81336251049 is a wasteful number, since it uses less digits than its factorization.

81336251049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061439.

The product of its (nonzero) digits is 155520, while the sum is 42.

The spelling of 81336251049 in words is "eighty-one billion, three hundred thirty-six million, two hundred fifty-one thousand, forty-nine".