81103331 has 2 divisors, whose sum is σ = 81103332. Its totient is φ = 81103330.

The previous prime is 81103307. The next prime is 81103369. The reversal of 81103331 is 13330118.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81103331 - 2¹⁴ = 81086947 is a prime.

It is a super-2 number, since 2×81103331² = 13155500598591122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81109331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40551665 + 40551666.

It is an arithmetic number, because the mean of its divisors is an integer number (40551666).

Almost surely, 2^81103331 is an apocalyptic number.

81103331 is a deficient number, since it is larger than the sum of its proper divisors (1).

81103331 is an equidigital number, since it uses as much as digits as its factorization.

81103331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 81103331 is about 9005.7387814660. The cubic root of 81103331 is about 432.8587794422.

Adding to 81103331 its reverse (13330118), we get a palindrome (94433449).

The spelling of 81103331 in words is "eighty-one million, one hundred three thousand, three hundred thirty-one".