81069257307 has 6 divisors (see below), whose sum is σ = 108093000628. Its totient is φ = 54045842764.

The previous prime is 81069257267. The next prime is 81069257327. The reversal of 81069257307 is 70375296018.

It is not a de Polignac number, because 81069257307 - 2¹⁰ = 81069256283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81069257327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 410968 + ... + 575354.

Almost surely, 2^81069257307 is an apocalyptic number.

81069257307 is a deficient number, since it is larger than the sum of its proper divisors (27023743321).

81069257307 is an frugal number, since it uses more digits than its factorization.

81069257307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328777 (or 164390 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 48.

Multiplying 81069257307 by its sum of digits (48), we get a square (3891324350736 = 1972644²).

The spelling of 81069257307 in words is "eighty-one billion, sixty-nine million, two hundred fifty-seven thousand, three hundred seven".