81095251 has 2 divisors, whose sum is σ = 81095252. Its totient is φ = 81095250.

The previous prime is 81095243. The next prime is 81095269. The reversal of 81095251 is 15259018.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81095251 - 2³ = 81095243 is a prime.

It is not a weakly prime, because it can be changed into another prime (81095221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40547625 + 40547626.

It is an arithmetic number, because the mean of its divisors is an integer number (40547626).

Almost surely, 2^81095251 is an apocalyptic number.

81095251 is a deficient number, since it is larger than the sum of its proper divisors (1).

81095251 is an equidigital number, since it uses as much as digits as its factorization.

81095251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 81095251 is about 9005.2901674516. The cubic root of 81095251 is about 432.8444043027.

The spelling of 81095251 in words is "eighty-one million, ninety-five thousand, two hundred fifty-one".