421745 has 4 divisors (see below), whose sum is σ = 506100. Its totient is φ = 337392.

The previous prime is 421741. The next prime is 421783. The reversal of 421745 is 547124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 187489 + 234256 = 433^2 + 484^2 .

It is a cyclic number.

It is not a de Polignac number, because 421745 - 2² = 421741 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 421745.

It is not an unprimeable number, because it can be changed into a prime (421741) 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, 42170 + ... + 42179.

It is an arithmetic number, because the mean of its divisors is an integer number (126525).

2⁴²¹⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

421745 is a deficient number, since it is larger than the sum of its proper divisors (84355).

421745 is an equidigital number, since it uses as much as digits as its factorization.

421745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84354.

The product of its digits is 1120, while the sum is 23.

The square root of 421745 is about 649.4189710811. The cubic root of 421745 is about 74.9922955049.

Adding to 421745 its reverse (547124), we get a palindrome (968869).

The spelling of 421745 in words is "four hundred twenty-one thousand, seven hundred forty-five".