81525277 has 2 divisors, whose sum is σ = 81525278. Its totient is φ = 81525276.

The previous prime is 81525263. The next prime is 81525287. The reversal of 81525277 is 77252518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56385081 + 25140196 = 7509^2 + 5014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81525277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81525247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40762638 + 40762639.

It is an arithmetic number, because the mean of its divisors is an integer number (40762639).

Almost surely, 2^81525277 is an apocalyptic number.

It is an amenable number.

81525277 is a deficient number, since it is larger than the sum of its proper divisors (1).

81525277 is an equidigital number, since it uses as much as digits as its factorization.

81525277 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39200, while the sum is 37.

The square root of 81525277 is about 9029.1348976522. The cubic root of 81525277 is about 433.6081412038.

The spelling of 81525277 in words is "eighty-one million, five hundred twenty-five thousand, two hundred seventy-seven".