421221423 has 32 divisors (see below), whose sum is σ = 649797120. Its totient is φ = 237744000.

The previous prime is 421221419. The next prime is 421221457. The reversal of 421221423 is 324122124.

It is not a de Polignac number, because 421221423 - 2² = 421221419 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 421221423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421221403) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 827293 + ... + 827801.

It is an arithmetic number, because the mean of its divisors is an integer number (20306160).

Almost surely, 2^421221423 is an apocalyptic number.

421221423 is a deficient number, since it is larger than the sum of its proper divisors (228575697).

421221423 is a wasteful number, since it uses less digits than its factorization.

421221423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 927.

The product of its digits is 768, while the sum is 21.

The square root of 421221423 is about 20523.6795677578. The cubic root of 421221423 is about 749.6124949320.

Adding to 421221423 its reverse (324122124), we get a palindrome (745343547).

The spelling of 421221423 in words is "four hundred twenty-one million, two hundred twenty-one thousand, four hundred twenty-three".