81307361 has 4 divisors (see below), whose sum is σ = 81672192. Its totient is φ = 80942532.

The previous prime is 81307337. The next prime is 81307399. The reversal of 81307361 is 16370318.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16370318 = 2 ⋅8185159.

It is a cyclic number.

It is not a de Polignac number, because 81307361 - 2⁶ = 81307297 is a prime.

It is a super-2 number, since 2×81307361² = 13221773905568642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81327361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182081 + ... + 182526.

It is an arithmetic number, because the mean of its divisors is an integer number (20418048).

Almost surely, 2^81307361 is an apocalyptic number.

It is an amenable number.

81307361 is a deficient number, since it is larger than the sum of its proper divisors (364831).

81307361 is a wasteful number, since it uses less digits than its factorization.

81307361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364830.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 81307361 is about 9017.0594430779. The cubic root of 81307361 is about 433.2214534969.

Adding to 81307361 its reverse (16370318), we get a palindrome (97677679).

The spelling of 81307361 in words is "eighty-one million, three hundred seven thousand, three hundred sixty-one".