427840 has 56 divisors (see below), whose sum is σ = 1170432. Its totient is φ = 145920.

The previous prime is 427813. The next prime is 427849. The reversal of 427840 is 48724.

It is a tau number, because it is divible by the number of its divisors (56).

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (427849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2145 + ... + 2335.

2⁴²⁷⁸⁴⁰ is an apocalyptic number.

427840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 427840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (585216).

427840 is an abundant number, since it is smaller than the sum of its proper divisors (742592).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

427840 is a wasteful number, since it uses less digits than its factorization.

427840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 25.

The square root of 427840 is about 654.0947943532. The cubic root of 427840 is about 75.3518284572.

The spelling of 427840 in words is "four hundred twenty-seven thousand, eight hundred forty".