71280421 has 2 divisors, whose sum is σ = 71280422. Its totient is φ = 71280420.

The previous prime is 71280413. The next prime is 71280431. The reversal of 71280421 is 12408217.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70308225 + 972196 = 8385^2 + 986^2 .

It is a cyclic number.

It is not a de Polignac number, because 71280421 - 2³ = 71280413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71280431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35640210 + 35640211.

It is an arithmetic number, because the mean of its divisors is an integer number (35640211).

Almost surely, 2^71280421 is an apocalyptic number.

It is an amenable number.

71280421 is a deficient number, since it is larger than the sum of its proper divisors (1).

71280421 is an equidigital number, since it uses as much as digits as its factorization.

71280421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 71280421 is about 8442.7733002847. The cubic root of 71280421 is about 414.6262100977.

Adding to 71280421 its reverse (12408217), we get a palindrome (83688638).

The spelling of 71280421 in words is "seventy-one million, two hundred eighty thousand, four hundred twenty-one".