81053257 has 2 divisors, whose sum is σ = 81053258. Its totient is φ = 81053256.

The previous prime is 81053233. The next prime is 81053261. The reversal of 81053257 is 75235018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79762761 + 1290496 = 8931^2 + 1136^2 .

It is a cyclic number.

It is not a de Polignac number, because 81053257 - 2⁷ = 81053129 is a prime.

It is not a weakly prime, because it can be changed into another prime (81053227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40526628 + 40526629.

It is an arithmetic number, because the mean of its divisors is an integer number (40526629).

Almost surely, 2^81053257 is an apocalyptic number.

It is an amenable number.

81053257 is a deficient number, since it is larger than the sum of its proper divisors (1).

81053257 is an equidigital number, since it uses as much as digits as its factorization.

81053257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 81053257 is about 9002.9582360466. The cubic root of 81053257 is about 432.7696773361.

The spelling of 81053257 in words is "eighty-one million, fifty-three thousand, two hundred fifty-seven".