81147097 has 2 divisors, whose sum is σ = 81147098. Its totient is φ = 81147096.

The previous prime is 81147091. The next prime is 81147109. The reversal of 81147097 is 79074118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74235456 + 6911641 = 8616^2 + 2629^2 .

It is a cyclic number.

It is not a de Polignac number, because 81147097 - 2³ = 81147089 is a prime.

It is not a weakly prime, because it can be changed into another prime (81147091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40573548 + 40573549.

It is an arithmetic number, because the mean of its divisors is an integer number (40573549).

Almost surely, 2^81147097 is an apocalyptic number.

It is an amenable number.

81147097 is a deficient number, since it is larger than the sum of its proper divisors (1).

81147097 is an equidigital number, since it uses as much as digits as its factorization.

81147097 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 81147097 is about 9008.1683487821. The cubic root of 81147097 is about 432.9366270080.

The spelling of 81147097 in words is "eighty-one million, one hundred forty-seven thousand, ninety-seven".