71891051 has 2 divisors, whose sum is σ = 71891052. Its totient is φ = 71891050.

The previous prime is 71891047. The next prime is 71891101. The reversal of 71891051 is 15019817.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 71891051 - 2² = 71891047 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 71890999 and 71891017.

It is not a weakly prime, because it can be changed into another prime (71851051) 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, 35945525 + 35945526.

It is an arithmetic number, because the mean of its divisors is an integer number (35945526).

Almost surely, 2^71891051 is an apocalyptic number.

71891051 is a deficient number, since it is larger than the sum of its proper divisors (1).

71891051 is an equidigital number, since it uses as much as digits as its factorization.

71891051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 32.

The square root of 71891051 is about 8478.8590623975. The cubic root of 71891051 is about 415.8068225217.

The spelling of 71891051 in words is "seventy-one million, eight hundred ninety-one thousand, fifty-one".