7071991 has 2 divisors, whose sum is σ = 7071992. Its totient is φ = 7071990.

The previous prime is 7071989. The next prime is 7071997. The reversal of 7071991 is 1991707.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (1991707) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7071991 - 2¹ = 7071989 is a prime.

Together with 7071989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7071997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3535995 + 3535996.

It is an arithmetic number, because the mean of its divisors is an integer number (3535996).

Almost surely, 2^7071991 is an apocalyptic number.

7071991 is a deficient number, since it is larger than the sum of its proper divisors (1).

7071991 is an equidigital number, since it uses as much as digits as its factorization.

7071991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3969, while the sum is 34.

The square root of 7071991 is about 2659.3215300148. The cubic root of 7071991 is about 191.9466630636.

The spelling of 7071991 in words is "seven million, seventy-one thousand, nine hundred ninety-one".