81321411 has 8 divisors (see below), whose sum is σ = 110266560. Its totient is φ = 53295272.

The previous prime is 81321407. The next prime is 81321431. The reversal of 81321411 is 11412318.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81321411 - 2² = 81321407 is a prime.

It is a super-2 number, since 2×81321411² = 13226343774061842, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81321431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 229545 + ... + 229898.

It is an arithmetic number, because the mean of its divisors is an integer number (13783320).

Almost surely, 2^81321411 is an apocalyptic number.

81321411 is a deficient number, since it is larger than the sum of its proper divisors (28945149).

81321411 is a wasteful number, since it uses less digits than its factorization.

81321411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459505.

The product of its digits is 192, while the sum is 21.

The square root of 81321411 is about 9017.8384882410. The cubic root of 81321411 is about 433.2464057717.

Adding to 81321411 its reverse (11412318), we get a palindrome (92733729).

The spelling of 81321411 in words is "eighty-one million, three hundred twenty-one thousand, four hundred eleven".