421653 has 4 divisors (see below), whose sum is σ = 562208. Its totient is φ = 281100.

The previous prime is 421643. The next prime is 421657. The reversal of 421653 is 356124.

It is a happy number.

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 not a de Polignac number, because 421653 - 2⁵ = 421621 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70273 + ... + 70278.

It is an arithmetic number, because the mean of its divisors is an integer number (140552).

2⁴²¹⁶⁵³ is an apocalyptic number.

It is an amenable number.

421653 is a deficient number, since it is larger than the sum of its proper divisors (140555).

421653 is a wasteful number, since it uses less digits than its factorization.

421653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140554.

The product of its digits is 720, while the sum is 21.

The square root of 421653 is about 649.3481346705. The cubic root of 421653 is about 74.9868421362.

Adding to 421653 its reverse (356124), we get a palindrome (777777).

The spelling of 421653 in words is "four hundred twenty-one thousand, six hundred fifty-three".