81411281 has 16 divisors (see below), whose sum is σ = 95679360. Its totient is φ = 67816320.

The previous prime is 81411269. The next prime is 81411289. The reversal of 81411281 is 18211418.

It is a cyclic number.

It is not a de Polignac number, because 81411281 - 2²² = 77216977 is a prime.

It is a super-2 number, since 2×81411281² = 13255593348121922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81411281.

It is not an unprimeable number, because it can be changed into a prime (81411289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 119915 + ... + 120591.

It is an arithmetic number, because the mean of its divisors is an integer number (5979960).

Almost surely, 2^81411281 is an apocalyptic number.

It is an amenable number.

81411281 is a deficient number, since it is larger than the sum of its proper divisors (14268079).

81411281 is a wasteful number, since it uses less digits than its factorization.

81411281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1144.

The product of its digits is 512, while the sum is 26.

The square root of 81411281 is about 9022.8200137208. The cubic root of 81411281 is about 433.4059435854.

Adding to 81411281 its reverse (18211418), we get a palindrome (99622699).

The spelling of 81411281 in words is "eighty-one million, four hundred eleven thousand, two hundred eighty-one".