420649 has 4 divisors (see below), whose sum is σ = 422100. Its totient is φ = 419200.

The previous prime is 420613. The next prime is 420671. The reversal of 420649 is 946024.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 403225 + 17424 = 635^2 + 132^2 .

It is a cyclic number.

It is not a de Polignac number, because 420649 - 2⁷ = 420521 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124 + ... + 925.

It is an arithmetic number, because the mean of its divisors is an integer number (105525).

2⁴²⁰⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

420649 is a deficient number, since it is larger than the sum of its proper divisors (1451).

420649 is a wasteful number, since it uses less digits than its factorization.

420649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1450.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 420649 is about 648.5745909300. The cubic root of 420649 is about 74.9272776571.

The spelling of 420649 in words is "four hundred twenty thousand, six hundred forty-nine".