421724 has 24 divisors (see below), whose sum is σ = 806400. Its totient is φ = 192240.

The previous prime is 421717. The next prime is 421727. The reversal of 421724 is 427124.

It is a super-2 number, since 2×421724² = 355702264352, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 421696 and 421705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421727) by changing a digit.

421724 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 7 ways as a sum of consecutive naturals, for example, 2267 + ... + 2445.

It is an arithmetic number, because the mean of its divisors is an integer number (33600).

2⁴²¹⁷²⁴ is an apocalyptic number.

It is an amenable number.

421724 is a deficient number, since it is larger than the sum of its proper divisors (384676).

421724 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 9 representation: 421724 = (712442)₉.

421724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 231 counting only the distinct ones).

The product of its digits is 448, while the sum is 20.

The square root of 421724 is about 649.4028025810. The cubic root of 421724 is about 74.9910507840.

Adding to 421724 its reverse (427124), we get a palindrome (848848).

The spelling of 421724 in words is "four hundred twenty-one thousand, seven hundred twenty-four", and thus it is an iban number.