81232531275761 has 4 divisors (see below), whose sum is σ = 81466630789872. Its totient is φ = 80998431761652.

The previous prime is 81232531275629. The next prime is 81232531275827. The reversal of 81232531275761 is 16757213523218.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81232531275761 - 2¹⁸ = 81232531013617 is a prime.

It is a super-2 number, since 2×81232531275761² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81232531278761) 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, 117049756535 + ... + 117049757228.

It is an arithmetic number, because the mean of its divisors is an integer number (20366657697468).

Almost surely, 2^{81232531275761} is an apocalyptic number.

It is an amenable number.

81232531275761 is a deficient number, since it is larger than the sum of its proper divisors (234099514111).

81232531275761 is a wasteful number, since it uses less digits than its factorization.

81232531275761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234099514110.

The product of its digits is 4233600, while the sum is 53.

Adding to 81232531275761 its reverse (16757213523218), we get a palindrome (97989744798979).

The spelling of 81232531275761 in words is "eighty-one trillion, two hundred thirty-two billion, five hundred thirty-one million, two hundred seventy-five thousand, seven hundred sixty-one".