81009297 has 6 divisors (see below), whose sum is σ = 117013442. Its totient is φ = 54006192.

The previous prime is 81009287. The next prime is 81009307. The reversal of 81009297 is 79290018.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81009287) and next prime (81009307).

It can be written as a sum of positive squares in only one way, i.e., 66194496 + 14814801 = 8136^2 + 3849^2 .

It is not a de Polignac number, because 81009297 - 2¹⁰ = 81008273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81009277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4500508 + ... + 4500525.

Almost surely, 2^81009297 is an apocalyptic number.

It is an amenable number.

81009297 is a deficient number, since it is larger than the sum of its proper divisors (36004145).

81009297 is a wasteful number, since it uses less digits than its factorization.

81009297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9001039 (or 9001036 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 81009297 is about 9000.5164851802. The cubic root of 81009297 is about 432.6914242790.

The spelling of 81009297 in words is "eighty-one million, nine thousand, two hundred ninety-seven".