648181 has 2 divisors, whose sum is σ = 648182. Its totient is φ = 648180.

The previous prime is 648173. The next prime is 648191. The reversal of 648181 is 181846.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 625681 + 22500 = 791^2 + 150^2 .

It is a cyclic number.

It is not a de Polignac number, because 648181 - 2³ = 648173 is a prime.

It is a super-2 number, since 2×648181² = 840277217522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (648101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324090 + 324091.

It is an arithmetic number, because the mean of its divisors is an integer number (324091).

2⁶⁴⁸¹⁸¹ is an apocalyptic number.

It is an amenable number.

648181 is a deficient number, since it is larger than the sum of its proper divisors (1).

648181 is an equidigital number, since it uses as much as digits as its factorization.

648181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 28.

The square root of 648181 is about 805.0968885793. The cubic root of 648181 is about 86.5430304799.

The spelling of 648181 in words is "six hundred forty-eight thousand, one hundred eighty-one".