81242597 has 4 divisors (see below), whose sum is σ = 81473100. Its totient is φ = 81012096.

The previous prime is 81242591. The next prime is 81242611. The reversal of 81242597 is 79524218.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 48455521 + 32787076 = 6961^2 + 5726^2 .

It is a cyclic number.

It is not a de Polignac number, because 81242597 - 2⁸ = 81242341 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81242597.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81242591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114722 + ... + 115427.

It is an arithmetic number, because the mean of its divisors is an integer number (20368275).

Almost surely, 2^81242597 is an apocalyptic number.

It is an amenable number.

81242597 is a deficient number, since it is larger than the sum of its proper divisors (230503).

81242597 is a wasteful number, since it uses less digits than its factorization.

81242597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230502.

The product of its digits is 40320, while the sum is 38.

The square root of 81242597 is about 9013.4675347504. The cubic root of 81242597 is about 433.1063978748.

The spelling of 81242597 in words is "eighty-one million, two hundred forty-two thousand, five hundred ninety-seven".