420278 has 4 divisors (see below), whose sum is σ = 630420. Its totient is φ = 210138.

The previous prime is 420271. The next prime is 420293. The reversal of 420278 is 872024.

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

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420271) by changing a digit.

420278 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105068 + ... + 105071.

It is an arithmetic number, because the mean of its divisors is an integer number (157605).

2⁴²⁰²⁷⁸ is an apocalyptic number.

420278 is a deficient number, since it is larger than the sum of its proper divisors (210142).

420278 is a wasteful number, since it uses less digits than its factorization.

420278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210141.

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 420278 is about 648.2885160174. The cubic root of 420278 is about 74.9052432956.

The spelling of 420278 in words is "four hundred twenty thousand, two hundred seventy-eight".