71002721 has 2 divisors, whose sum is σ = 71002722. Its totient is φ = 71002720.

The previous prime is 71002717. The next prime is 71002747. The reversal of 71002721 is 12720017.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58675600 + 12327121 = 7660^2 + 3511^2 .

It is a cyclic number.

It is not a de Polignac number, because 71002721 - 2² = 71002717 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 71002693 and 71002702.

It is not a weakly prime, because it can be changed into another prime (71002021) 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, 35501360 + 35501361.

It is an arithmetic number, because the mean of its divisors is an integer number (35501361).

Almost surely, 2^71002721 is an apocalyptic number.

It is an amenable number.

71002721 is a deficient number, since it is larger than the sum of its proper divisors (1).

71002721 is an equidigital number, since it uses as much as digits as its factorization.

71002721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 71002721 is about 8426.3112332740. The cubic root of 71002721 is about 414.0870646236.

Adding to 71002721 its reverse (12720017), we get a palindrome (83722738).

The spelling of 71002721 in words is "seventy-one million, two thousand, seven hundred twenty-one".