81624026161 has 2 divisors, whose sum is σ = 81624026162. Its totient is φ = 81624026160.

The previous prime is 81624026059. The next prime is 81624026167. The reversal of 81624026161 is 16162042618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64049486400 + 17574539761 = 253080^2 + 132569^2 .

It is a cyclic number.

It is not a de Polignac number, because 81624026161 - 2⁹ = 81624025649 is a prime.

It is a super-2 number, since 2×81624026161² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81624026161.

It is not a weakly prime, because it can be changed into another prime (81624026167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40812013080 + 40812013081.

It is an arithmetic number, because the mean of its divisors is an integer number (40812013081).

Almost surely, 2^81624026161 is an apocalyptic number.

It is an amenable number.

81624026161 is a deficient number, since it is larger than the sum of its proper divisors (1).

81624026161 is an equidigital number, since it uses as much as digits as its factorization.

81624026161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 37.

Adding to 81624026161 its reverse (16162042618), we get a palindrome (97786068779).

The spelling of 81624026161 in words is "eighty-one billion, six hundred twenty-four million, twenty-six thousand, one hundred sixty-one".