81163633 has 2 divisors, whose sum is σ = 81163634. Its totient is φ = 81163632.

The previous prime is 81163597. The next prime is 81163697. The reversal of 81163633 is 33636118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47430769 + 33732864 = 6887^2 + 5808^2 .

It is a cyclic number.

It is not a de Polignac number, because 81163633 - 2¹⁷ = 81032561 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81163595 and 81163604.

It is not a weakly prime, because it can be changed into another prime (81163133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40581816 + 40581817.

It is an arithmetic number, because the mean of its divisors is an integer number (40581817).

Almost surely, 2^81163633 is an apocalyptic number.

It is an amenable number.

81163633 is a deficient number, since it is larger than the sum of its proper divisors (1).

81163633 is an equidigital number, since it uses as much as digits as its factorization.

81163633 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 31.

The square root of 81163633 is about 9009.0861356744. The cubic root of 81163633 is about 432.9660326762.

It can be divided in two parts, 81163 and 633, that added together give a square (81796 = 286²).

The spelling of 81163633 in words is "eighty-one million, one hundred sixty-three thousand, six hundred thirty-three".