81718595227 has 4 divisors (see below), whose sum is σ = 84354678976. Its totient is φ = 79082511480.

The previous prime is 81718595219. The next prime is 81718595237. The reversal of 81718595227 is 72259581718.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81718595227 - 2³ = 81718595219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81718595237) 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, 1318041828 + ... + 1318041889.

It is an arithmetic number, because the mean of its divisors is an integer number (21088669744).

Almost surely, 2^81718595227 is an apocalyptic number.

81718595227 is a deficient number, since it is larger than the sum of its proper divisors (2636083749).

81718595227 is a wasteful number, since it uses less digits than its factorization.

81718595227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2636083748.

The product of its digits is 2822400, while the sum is 55.

The spelling of 81718595227 in words is "eighty-one billion, seven hundred eighteen million, five hundred ninety-five thousand, two hundred twenty-seven".