71263721 has 2 divisors, whose sum is σ = 71263722. Its totient is φ = 71263720.

The previous prime is 71263697. The next prime is 71263723. The reversal of 71263721 is 12736217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69973225 + 1290496 = 8365^2 + 1136^2 .

It is a cyclic number.

It is not a de Polignac number, because 71263721 - 2⁶ = 71263657 is a prime.

It is a Sophie Germain prime.

Together with 71263723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (71263723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35631860 + 35631861.

It is an arithmetic number, because the mean of its divisors is an integer number (35631861).

Almost surely, 2^71263721 is an apocalyptic number.

It is an amenable number.

71263721 is a deficient number, since it is larger than the sum of its proper divisors (1).

71263721 is an equidigital number, since it uses as much as digits as its factorization.

71263721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3528, while the sum is 29.

The square root of 71263721 is about 8441.7842308365. The cubic root of 71263721 is about 414.5938272056.

Adding to 71263721 its reverse (12736217), we get a palindrome (83999938).

The spelling of 71263721 in words is "seventy-one million, two hundred sixty-three thousand, seven hundred twenty-one".