81075157 has 2 divisors, whose sum is σ = 81075158. Its totient is φ = 81075156.

The previous prime is 81075139. The next prime is 81075179. The reversal of 81075157 is 75157018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41460721 + 39614436 = 6439^2 + 6294^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81075157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81075257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40537578 + 40537579.

It is an arithmetic number, because the mean of its divisors is an integer number (40537579).

Almost surely, 2^81075157 is an apocalyptic number.

It is an amenable number.

81075157 is a deficient number, since it is larger than the sum of its proper divisors (1).

81075157 is an equidigital number, since it uses as much as digits as its factorization.

81075157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9800, while the sum is 34.

The square root of 81075157 is about 9004.1744207895. The cubic root of 81075157 is about 432.8086508983.

The spelling of 81075157 in words is "eighty-one million, seventy-five thousand, one hundred fifty-seven".