647481421 has 2 divisors, whose sum is σ = 647481422. Its totient is φ = 647481420.

The previous prime is 647481377. The next prime is 647481479. The reversal of 647481421 is 124184746.

It is a happy number.

647481421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 586172521 + 61308900 = 24211^2 + 7830^2 .

It is a cyclic number.

It is not a de Polignac number, because 647481421 - 2²¹ = 645384269 is a prime.

It is equal to p_33669271 and since 647481421 and 33669271 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647481481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323740710 + 323740711.

It is an arithmetic number, because the mean of its divisors is an integer number (323740711).

Almost surely, 2^647481421 is an apocalyptic number.

It is an amenable number.

647481421 is a deficient number, since it is larger than the sum of its proper divisors (1).

647481421 is an equidigital number, since it uses as much as digits as its factorization.

647481421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43008, while the sum is 37.

The square root of 647481421 is about 25445.6562304846. The cubic root of 647481421 is about 865.1188409675.

The spelling of 647481421 in words is "six hundred forty-seven million, four hundred eighty-one thousand, four hundred twenty-one".