421928 has 16 divisors (see below), whose sum is σ = 852180. Its totient is φ = 194688.

The previous prime is 421913. The next prime is 421943. The reversal of 421928 is 829124.

421928 = T₁₆₇ + T₁₆₈ + ... + T₁₉₂.

It is an interprime number because it is at equal distance from previous prime (421913) and next prime (421943).

It can be written as a sum of positive squares in 2 ways, for example, as 407044 + 14884 = 638^2 + 122^2 .

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 421897 and 421906.

It is an unprimeable number.

421928 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 (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1925 + ... + 2132.

2⁴²¹⁹²⁸ is an apocalyptic number.

It is an amenable number.

421928 is an abundant number, since it is smaller than the sum of its proper divisors (430252).

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

421928 is a wasteful number, since it uses less digits than its factorization.

421928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4076 (or 4072 counting only the distinct ones).

The product of its digits is 1152, while the sum is 26.

The square root of 421928 is about 649.5598509760. The cubic root of 421928 is about 75.0031406092.

The spelling of 421928 in words is "four hundred twenty-one thousand, nine hundred twenty-eight".