71280221 has 2 divisors, whose sum is σ = 71280222. Its totient is φ = 71280220.

The previous prime is 71280211. The next prime is 71280227. The reversal of 71280221 is 12208217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47416996 + 23863225 = 6886^2 + 4885^2 .

It is a cyclic number.

It is not a de Polignac number, because 71280221 - 2¹⁴ = 71263837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71280227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35640110 + 35640111.

It is an arithmetic number, because the mean of its divisors is an integer number (35640111).

Almost surely, 2^71280221 is an apocalyptic number.

It is an amenable number.

71280221 is a deficient number, since it is larger than the sum of its proper divisors (1).

71280221 is an equidigital number, since it uses as much as digits as its factorization.

71280221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 71280221 is about 8442.7614558271. The cubic root of 71280221 is about 414.6258223085.

Adding to 71280221 its reverse (12208217), we get a palindrome (83488438).

The spelling of 71280221 in words is "seventy-one million, two hundred eighty thousand, two hundred twenty-one".