421121321 has 4 divisors (see below), whose sum is σ = 421538052. Its totient is φ = 420704592.

The previous prime is 421121303. The next prime is 421121347. The reversal of 421121321 is 123121124.

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 163968025 + 257153296 = 12805^2 + 16036^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421121321 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 421121321.

It is not an unprimeable number, because it can be changed into a prime (421121381) 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, 206846 + ... + 208871.

It is an arithmetic number, because the mean of its divisors is an integer number (105384513).

Almost surely, 2^421121321 is an apocalyptic number.

It is an amenable number.

421121321 is a deficient number, since it is larger than the sum of its proper divisors (416731).

421121321 is a wasteful number, since it uses less digits than its factorization.

421121321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416730.

The product of its digits is 96, while the sum is 17.

The square root of 421121321 is about 20521.2407275973. The cubic root of 421121321 is about 749.5531091784.

Adding to 421121321 its reverse (123121124), we get a palindrome (544242445).

The spelling of 421121321 in words is "four hundred twenty-one million, one hundred twenty-one thousand, three hundred twenty-one".