81228841 has 2 divisors, whose sum is σ = 81228842. Its totient is φ = 81228840.

The previous prime is 81228803. The next prime is 81228853. The reversal of 81228841 is 14882218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43283241 + 37945600 = 6579^2 + 6160^2 .

It is a cyclic number.

It is not a de Polignac number, because 81228841 - 2⁷ = 81228713 is a prime.

It is a super-2 number, since 2×81228841² = 13196249220406562, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81228797 and 81228806.

It is not a weakly prime, because it can be changed into another prime (81228041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40614420 + 40614421.

It is an arithmetic number, because the mean of its divisors is an integer number (40614421).

Almost surely, 2^81228841 is an apocalyptic number.

It is an amenable number.

81228841 is a deficient number, since it is larger than the sum of its proper divisors (1).

81228841 is an equidigital number, since it uses as much as digits as its factorization.

81228841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8192, while the sum is 34.

The square root of 81228841 is about 9012.7044220922. The cubic root of 81228841 is about 433.0819519638.

The spelling of 81228841 in words is "eighty-one million, two hundred twenty-eight thousand, eight hundred forty-one".