71705891 has 2 divisors, whose sum is σ = 71705892. Its totient is φ = 71705890.

The previous prime is 71705839. The next prime is 71705899. The reversal of 71705891 is 19850717.

It is a strong prime.

It is an emirp because it is prime and its reverse (19850717) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71705891 - 2²⁶ = 4597027 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (71705899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35852945 + 35852946.

It is an arithmetic number, because the mean of its divisors is an integer number (35852946).

Almost surely, 2^71705891 is an apocalyptic number.

71705891 is a deficient number, since it is larger than the sum of its proper divisors (1).

71705891 is an equidigital number, since it uses as much as digits as its factorization.

71705891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17640, while the sum is 38.

The square root of 71705891 is about 8467.9331008222. The cubic root of 71705891 is about 415.4495365861.

The spelling of 71705891 in words is "seventy-one million, seven hundred five thousand, eight hundred ninety-one".