71945891 has 2 divisors, whose sum is σ = 71945892. Its totient is φ = 71945890.

The previous prime is 71945869. The next prime is 71945903. The reversal of 71945891 is 19854917.

It is a strong prime.

It is an emirp because it is prime and its reverse (19854917) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71945891 - 2⁶ = 71945827 is a prime.

It is a super-2 number, since 2×71945891² = 10352422463567762, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (71945851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35972945 + 35972946.

It is an arithmetic number, because the mean of its divisors is an integer number (35972946).

Almost surely, 2^71945891 is an apocalyptic number.

71945891 is a deficient number, since it is larger than the sum of its proper divisors (1).

71945891 is an equidigital number, since it uses as much as digits as its factorization.

71945891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 44.

The square root of 71945891 is about 8482.0923715791. The cubic root of 71945891 is about 415.9125243678.

The spelling of 71945891 in words is "seventy-one million, nine hundred forty-five thousand, eight hundred ninety-one".