81275003020225 has 135 divisors (see below), whose sum is σ = 121588225069731. Its totient is φ = 53888205621600.

The previous prime is 81275003020069. The next prime is 81275003020229. The reversal of 81275003020225 is 52202030057218.

The square root of 81275003020225 is 9015265.

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

It can be written as a sum of positive squares in only one way, i.e., 29259001087281 + 52016001932944 = 5409159^2 + 7212212^2 .

It is not a de Polignac number, because 81275003020225 - 2⁹ = 81275003019713 is a prime.

It is a super-2 number, since 2×81275003020225² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81275003020229) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 68470937082 + ... + 68470938268.

Almost surely, 2^{81275003020225} is an apocalyptic number.

81275003020225 is the 9015265-th square number.

81275003020225 is the 4507633-rd centered octagonal number.

It is an amenable number.

81275003020225 is a deficient number, since it is larger than the sum of its proper divisors (40313222049506).

81275003020225 is an frugal number, since it uses more digits than its factorization.

81275003020225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2474 (or 1230 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 37.

The spelling of 81275003020225 in words is "eighty-one trillion, two hundred seventy-five billion, three million, twenty thousand, two hundred twenty-five".