81455686331 has 4 divisors (see below), whose sum is σ = 81955414632. Its totient is φ = 80955958032.

The previous prime is 81455686309. The next prime is 81455686399. The reversal of 81455686331 is 13368655418.

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 81455686331 - 2⁶ = 81455686267 is a prime.

It is a super-2 number, since 2×81455686331² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81455686331.

It is not an unprimeable number, because it can be changed into a prime (81455686231) 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, 249863906 + ... + 249864231.

It is an arithmetic number, because the mean of its divisors is an integer number (20488853658).

Almost surely, 2^81455686331 is an apocalyptic number.

81455686331 is a deficient number, since it is larger than the sum of its proper divisors (499728301).

81455686331 is a wasteful number, since it uses less digits than its factorization.

81455686331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499728300.

The product of its digits is 2073600, while the sum is 50.

The spelling of 81455686331 in words is "eighty-one billion, four hundred fifty-five million, six hundred eighty-six thousand, three hundred thirty-one".