71661089 has 2 divisors, whose sum is σ = 71661090. Its totient is φ = 71661088.

The previous prime is 71661049. The next prime is 71661101. The reversal of 71661089 is 98016617.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51724864 + 19936225 = 7192^2 + 4465^2 .

It is an emirp because it is prime and its reverse (98016617) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71661089 - 2¹² = 71656993 is a prime.

It is not a weakly prime, because it can be changed into another prime (71661019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35830544 + 35830545.

It is an arithmetic number, because the mean of its divisors is an integer number (35830545).

Almost surely, 2^71661089 is an apocalyptic number.

It is an amenable number.

71661089 is a deficient number, since it is larger than the sum of its proper divisors (1).

71661089 is an equidigital number, since it uses as much as digits as its factorization.

71661089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 71661089 is about 8465.2872957744. The cubic root of 71661089 is about 415.3629939618.

The spelling of 71661089 in words is "seventy-one million, six hundred sixty-one thousand, eighty-nine".