81875597 has 2 divisors, whose sum is σ = 81875598. Its totient is φ = 81875596.

The previous prime is 81875543. The next prime is 81875609. The reversal of 81875597 is 79557818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77334436 + 4541161 = 8794^2 + 2131^2 .

It is a cyclic number.

It is not a de Polignac number, because 81875597 - 2⁸ = 81875341 is a prime.

It is a super-2 number, since 2×81875597² = 13407226768212818, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81875527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40937798 + 40937799.

It is an arithmetic number, because the mean of its divisors is an integer number (40937799).

Almost surely, 2^81875597 is an apocalyptic number.

It is an amenable number.

81875597 is a deficient number, since it is larger than the sum of its proper divisors (1).

81875597 is an equidigital number, since it uses as much as digits as its factorization.

81875597 is an evil number, because the sum of its binary digits is even.

The product of its digits is 705600, while the sum is 50.

The square root of 81875597 is about 9048.5135243309. The cubic root of 81875597 is about 434.2283355376.

The spelling of 81875597 in words is "eighty-one million, eight hundred seventy-five thousand, five hundred ninety-seven".