81253057 has 2 divisors, whose sum is σ = 81253058. Its totient is φ = 81253056.

The previous prime is 81253049. The next prime is 81253079. The reversal of 81253057 is 75035218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73685056 + 7568001 = 8584^2 + 2751^2 .

It is a cyclic number.

It is not a de Polignac number, because 81253057 - 2³ = 81253049 is a prime.

It is not a weakly prime, because it can be changed into another prime (81253087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40626528 + 40626529.

It is an arithmetic number, because the mean of its divisors is an integer number (40626529).

Almost surely, 2^81253057 is an apocalyptic number.

It is an amenable number.

81253057 is a deficient number, since it is larger than the sum of its proper divisors (1).

81253057 is an equidigital number, since it uses as much as digits as its factorization.

81253057 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 81253057 is about 9014.0477589150. The cubic root of 81253057 is about 433.1249845879.

The spelling of 81253057 in words is "eighty-one million, two hundred fifty-three thousand, fifty-seven".