81569495349 has 6 divisors (see below), whose sum is σ = 117822604406. Its totient is φ = 54379663560.

The previous prime is 81569495339. The next prime is 81569495383. The reversal of 81569495349 is 94359496518.

81569495349 is a `hidden beast` number, since 8 + 1 + 5 + 6 + 94 + 9 + 534 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 64543943025 + 17025552324 = 254055^2 + 130482^2 .

It is not a de Polignac number, because 81569495349 - 2⁵ = 81569495317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81569495309) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4531638622 + ... + 4531638639.

Almost surely, 2^81569495349 is an apocalyptic number.

It is an amenable number.

81569495349 is a deficient number, since it is larger than the sum of its proper divisors (36253109057).

81569495349 is a wasteful number, since it uses less digits than its factorization.

81569495349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9063277267 (or 9063277264 counting only the distinct ones).

The product of its digits is 41990400, while the sum is 63.

The spelling of 81569495349 in words is "eighty-one billion, five hundred sixty-nine million, four hundred ninety-five thousand, three hundred forty-nine".