669481 has 2 divisors, whose sum is σ = 669482. Its totient is φ = 669480.

The previous prime is 669479. The next prime is 669527. The reversal of 669481 is 184966.

669481 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., 403225 + 266256 = 635^2 + 516^2 .

It is a cyclic number.

It is not a de Polignac number, because 669481 - 2¹ = 669479 is a prime.

It is a super-2 number, since 2×669481² = 896409618722, which contains 22 as substring.

Together with 669479, it forms a pair of twin primes.

669481 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (669401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334740 + 334741.

It is an arithmetic number, because the mean of its divisors is an integer number (334741).

2⁶⁶⁹⁴⁸¹ is an apocalyptic number.

It is an amenable number.

669481 is a deficient number, since it is larger than the sum of its proper divisors (1).

669481 is an equidigital number, since it uses as much as digits as its factorization.

669481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 34.

The square root of 669481 is about 818.2181860604. The cubic root of 669481 is about 87.4808012300.

The spelling of 669481 in words is "six hundred sixty-nine thousand, four hundred eighty-one".