421904 has 20 divisors (see below), whose sum is σ = 934464. Its totient is φ = 180768.

The previous prime is 421891. The next prime is 421907. The reversal of 421904 is 409124.

It is not an unprimeable number, because it can be changed into a prime (421907) by changing a digit.

421904 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1772 + ... + 1995.

2⁴²¹⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

421904 is an abundant number, since it is smaller than the sum of its proper divisors (512560).

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

421904 is a wasteful number, since it uses less digits than its factorization.

421904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3782 (or 3776 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 421904 is about 649.5413766651. The cubic root of 421904 is about 75.0017184791.

It can be divided in two parts, 4 and 21904, that multiplied together give a square (87616 = 296²).

The spelling of 421904 in words is "four hundred twenty-one thousand, nine hundred four".