421537 has 4 divisors (see below), whose sum is σ = 423936. Its totient is φ = 419140.

The previous prime is 421517. The next prime is 421559. The reversal of 421537 is 735124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 421537 - 2⁷ = 421409 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (421517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 913 + ... + 1294.

It is an arithmetic number, because the mean of its divisors is an integer number (105984).

2⁴²¹⁵³⁷ is an apocalyptic number.

It is an amenable number.

421537 is a deficient number, since it is larger than the sum of its proper divisors (2399).

421537 is a wasteful number, since it uses less digits than its factorization.

421537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2398.

The product of its digits is 840, while the sum is 22.

The square root of 421537 is about 649.2588081805. The cubic root of 421537 is about 74.9799650188.

The spelling of 421537 in words is "four hundred twenty-one thousand, five hundred thirty-seven".