81139395307 has 16 divisors (see below), whose sum is σ = 84704590080. Its totient is φ = 77627149600.

The previous prime is 81139395301. The next prime is 81139395383. The reversal of 81139395307 is 70359393118.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81139395307 - 2³ = 81139395299 is a prime.

It is a super-2 number, since 2×81139395307² (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 (81139395301) 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 15 ways as a sum of consecutive naturals, for example, 2579082 + ... + 2610352.

It is an arithmetic number, because the mean of its divisors is an integer number (5294036880).

Almost surely, 2^81139395307 is an apocalyptic number.

81139395307 is a deficient number, since it is larger than the sum of its proper divisors (3565194773).

81139395307 is a wasteful number, since it uses less digits than its factorization.

81139395307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32114.

The product of its (nonzero) digits is 612360, while the sum is 49.

The spelling of 81139395307 in words is "eighty-one billion, one hundred thirty-nine million, three hundred ninety-five thousand, three hundred seven".