81102496225 has 9 divisors (see below), whose sum is σ = 100568861017. Its totient is φ = 64880857840.

The previous prime is 81102496217. The next prime is 81102496243. The reversal of 81102496225 is 52269420118.

It is a happy number.

The square root of 81102496225 is 284785.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 25851173089 + 55251323136 = 160783^2 + 235056^2 .

It is not a de Polignac number, because 81102496225 - 2³ = 81102496217 is a prime.

It is a super-2 number, since 2×81102496225² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

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 in 8 ways as a sum of consecutive naturals, for example, 1395447 + ... + 1452403.

Almost surely, 2^81102496225 is an apocalyptic number.

81102496225 is the 284785-th square number.

81102496225 is the 142393-rd centered octagonal number.

It is an amenable number.

81102496225 is a deficient number, since it is larger than the sum of its proper divisors (19466364792).

81102496225 is an frugal number, since it uses more digits than its factorization.

81102496225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113924 (or 56962 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 40.

The spelling of 81102496225 in words is "eighty-one billion, one hundred two million, four hundred ninety-six thousand, two hundred twenty-five".