81299346058225 has 9 divisors (see below), whose sum is σ = 100811245015243. Its totient is φ = 65039440780120.

The previous prime is 81299346058207. The next prime is 81299346058243. The reversal of 81299346058225 is 52285064399218.

The square root of 81299346058225 is 9016615.

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

It is an interprime number because it is at equal distance from previous prime (81299346058207) and next prime (81299346058243).

It can be written as a sum of positive squares in only one way, i.e., 29267764580961 + 52031581477264 = 5409969^2 + 7213292^2 .

It is not a de Polignac number, because 81299346058225 - 2¹⁹ = 81299345533937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 44181414 + ... + 45984736.

Almost surely, 2^{81299346058225} is an apocalyptic number.

81299346058225 is the 9016615-th square number.

81299346058225 is the 4508308-th centered octagonal number.

It is an amenable number.

81299346058225 is a deficient number, since it is larger than the sum of its proper divisors (19511898957018).

81299346058225 is an frugal number, since it uses more digits than its factorization.

81299346058225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3606656 (or 1803328 counting only the distinct ones).

The product of its (nonzero) digits is 74649600, while the sum is 64.

The spelling of 81299346058225 in words is "eighty-one trillion, two hundred ninety-nine billion, three hundred forty-six million, fifty-eight thousand, two hundred twenty-five".