81397703169 has 32 divisors (see below), whose sum is σ = 120932423040. Its totient is φ = 54110923776.

The previous prime is 81397703161. The next prime is 81397703183. The reversal of 81397703169 is 96130779318.

It is not a de Polignac number, because 81397703169 - 2³ = 81397703161 is a prime.

It is a super-2 number, since 2×81397703169² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81397703161) 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 31 ways as a sum of consecutive naturals, for example, 15569934 + ... + 15575160.

It is an arithmetic number, because the mean of its divisors is an integer number (3779138220).

Almost surely, 2^81397703169 is an apocalyptic number.

It is an amenable number.

81397703169 is a deficient number, since it is larger than the sum of its proper divisors (39534719871).

81397703169 is a wasteful number, since it uses less digits than its factorization.

81397703169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6766 (or 6760 counting only the distinct ones).

The product of its (nonzero) digits is 1714608, while the sum is 54.

The spelling of 81397703169 in words is "eighty-one billion, three hundred ninety-seven million, seven hundred three thousand, one hundred sixty-nine".