421321403 has 4 divisors (see below), whose sum is σ = 434912448. Its totient is φ = 407730360.

The previous prime is 421321391. The next prime is 421321451. The reversal of 421321403 is 304123124.

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

It is a cyclic number.

It is not a de Polignac number, because 421321403 - 2¹⁸ = 421059259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (421321463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6795476 + ... + 6795537.

It is an arithmetic number, because the mean of its divisors is an integer number (108728112).

Almost surely, 2^421321403 is an apocalyptic number.

421321403 is a deficient number, since it is larger than the sum of its proper divisors (13591045).

421321403 is a wasteful number, since it uses less digits than its factorization.

421321403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13591044.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 421321403 is about 20526.1151463203. The cubic root of 421321403 is about 749.6717989182.

Adding to 421321403 its reverse (304123124), we get a palindrome (725444527).

The spelling of 421321403 in words is "four hundred twenty-one million, three hundred twenty-one thousand, four hundred three".