71238821 has 2 divisors, whose sum is σ = 71238822. Its totient is φ = 71238820.

The previous prime is 71238787. The next prime is 71238829. The reversal of 71238821 is 12883217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37761025 + 33477796 = 6145^2 + 5786^2 .

It is a cyclic number.

It is not a de Polignac number, because 71238821 - 2⁶ = 71238757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71238829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35619410 + 35619411.

It is an arithmetic number, because the mean of its divisors is an integer number (35619411).

Almost surely, 2^71238821 is an apocalyptic number.

It is an amenable number.

71238821 is a deficient number, since it is larger than the sum of its proper divisors (1).

71238821 is an equidigital number, since it uses as much as digits as its factorization.

71238821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5376, while the sum is 32.

The square root of 71238821 is about 8440.3092952806. The cubic root of 71238821 is about 414.5455343354.

The spelling of 71238821 in words is "seventy-one million, two hundred thirty-eight thousand, eight hundred twenty-one".