423421021 has 8 divisors (see below), whose sum is σ = 426014424. Its totient is φ = 420836160.

The previous prime is 423421013. The next prime is 423421049. The reversal of 423421021 is 120124324.

It can be written as a sum of positive squares in 4 ways, for example, as 54243225 + 369177796 = 7365^2 + 19214^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 423421021 - 2³ = 423421013 is a prime.

It is a super-2 number, since 2×423421021² = 358570722049364882, which contains 22 as substring.

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 423421021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (423421051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 116451 + ... + 120031.

It is an arithmetic number, because the mean of its divisors is an integer number (53251803).

Almost surely, 2^423421021 is an apocalyptic number.

It is an amenable number.

423421021 is a deficient number, since it is larger than the sum of its proper divisors (2593403).

423421021 is a wasteful number, since it uses less digits than its factorization.

423421021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4271.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 423421021 is about 20577.1966263629. The cubic root of 423421021 is about 750.9150437319.

Adding to 423421021 its reverse (120124324), we get a palindrome (543545345).

The spelling of 423421021 in words is "four hundred twenty-three million, four hundred twenty-one thousand, twenty-one".