81257297 has 16 divisors (see below), whose sum is σ = 94146624. Its totient is φ = 69312000.

The previous prime is 81257287. The next prime is 81257311. The reversal of 81257297 is 79275218.

It is a cyclic number.

It is not a de Polignac number, because 81257297 - 2¹⁸ = 80995153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81257237) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106397 + ... + 107157.

It is an arithmetic number, because the mean of its divisors is an integer number (5884164).

Almost surely, 2^81257297 is an apocalyptic number.

It is an amenable number.

81257297 is a deficient number, since it is larger than the sum of its proper divisors (12889327).

81257297 is a wasteful number, since it uses less digits than its factorization.

81257297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360.

The product of its digits is 70560, while the sum is 41.

The square root of 81257297 is about 9014.2829443057. The cubic root of 81257297 is about 433.1325183269.

The spelling of 81257297 in words is "eighty-one million, two hundred fifty-seven thousand, two hundred ninety-seven".