81307083727 has 4 divisors (see below), whose sum is σ = 86089853376. Its totient is φ = 76524314080.

The previous prime is 81307083679. The next prime is 81307083779. The reversal of 81307083727 is 72738070318.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-81307083727 is a prime.

It is a super-2 number, since 2×81307083727² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81307080727) 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, 2391384799 + ... + 2391384832.

It is an arithmetic number, because the mean of its divisors is an integer number (21522463344).

Almost surely, 2^81307083727 is an apocalyptic number.

81307083727 is a deficient number, since it is larger than the sum of its proper divisors (4782769649).

81307083727 is a wasteful number, since it uses less digits than its factorization.

81307083727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4782769648.

The product of its (nonzero) digits is 395136, while the sum is 46.

The spelling of 81307083727 in words is "eighty-one billion, three hundred seven million, eighty-three thousand, seven hundred twenty-seven".