81569135403919 has 6 divisors (see below), whose sum is σ = 82384746806360. Its totient is φ = 80761520191800.

The previous prime is 81569135403887. The next prime is 81569135403929. The reversal of 81569135403919 is 91930453196518.

It is not a de Polignac number, because 81569135403919 - 2⁵ = 81569135403887 is a prime.

It is a super-2 number, since 2×81569135403919² (a number of 29 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 (81569135403929) 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, 3998084859 + ... + 3998105260.

Almost surely, 2^{81569135403919} is an apocalyptic number.

81569135403919 is a deficient number, since it is larger than the sum of its proper divisors (815611402441).

81569135403919 is an equidigital number, since it uses as much as digits as its factorization.

81569135403919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7996190321 (or 7996190220 counting only the distinct ones).

The product of its (nonzero) digits is 31492800, while the sum is 64.

The spelling of 81569135403919 in words is "eighty-one trillion, five hundred sixty-nine billion, one hundred thirty-five million, four hundred three thousand, nine hundred nineteen".