81035870225 has 12 divisors (see below), whose sum is σ = 100488164700. Its totient is φ = 64826318400.

The previous prime is 81035870221. The next prime is 81035870233. The reversal of 81035870225 is 52207853018.

It is a Cunningham number, because it is equal to 284668²+1.

It can be written as a sum of positive squares in 6 ways, for example, as 1 + 81035870224 = 1^2 + 284668^2 .

It is not a de Polignac number, because 81035870225 - 2² = 81035870221 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81035870221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1020455 + ... + 1096995.

It is an arithmetic number, because the mean of its divisors is an integer number (8374013725).

Almost surely, 2^81035870225 is an apocalyptic number.

It is an amenable number.

81035870225 is a deficient number, since it is larger than the sum of its proper divisors (19452294475).

81035870225 is a wasteful number, since it uses less digits than its factorization.

81035870225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118900 (or 118895 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 41.

The spelling of 81035870225 in words is "eighty-one billion, thirty-five million, eight hundred seventy thousand, two hundred twenty-five".