71995891 has 4 divisors (see below), whose sum is σ = 78540984. Its totient is φ = 65450800.

The previous prime is 71995849. The next prime is 71995909. The reversal of 71995891 is 19859917.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 71995891 - 2¹¹ = 71993843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71995801) 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 in 3 ways as a sum of consecutive naturals, for example, 3272530 + ... + 3272551.

It is an arithmetic number, because the mean of its divisors is an integer number (19635246).

Almost surely, 2^71995891 is an apocalyptic number.

71995891 is a deficient number, since it is larger than the sum of its proper divisors (6545093).

71995891 is a wasteful number, since it uses less digits than its factorization.

71995891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6545092.

The product of its digits is 204120, while the sum is 49.

The square root of 71995891 is about 8485.0392456370. The cubic root of 71995891 is about 416.0088505113.

The spelling of 71995891 in words is "seventy-one million, nine hundred ninety-five thousand, eight hundred ninety-one".