81722464601 has 2 divisors, whose sum is σ = 81722464602. Its totient is φ = 81722464600.

The previous prime is 81722464597. The next prime is 81722464627. The reversal of 81722464601 is 10646422718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73345638976 + 8376825625 = 270824^2 + 91525^2 .

It is a cyclic number.

It is not a de Polignac number, because 81722464601 - 2² = 81722464597 is a prime.

It is a super-2 number, since 2×81722464601² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81722464301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40861232300 + 40861232301.

It is an arithmetic number, because the mean of its divisors is an integer number (40861232301).

Almost surely, 2^81722464601 is an apocalyptic number.

It is an amenable number.

81722464601 is a deficient number, since it is larger than the sum of its proper divisors (1).

81722464601 is an equidigital number, since it uses as much as digits as its factorization.

81722464601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129024, while the sum is 41.

The spelling of 81722464601 in words is "eighty-one billion, seven hundred twenty-two million, four hundred sixty-four thousand, six hundred one".