421823839 has 4 divisors (see below), whose sum is σ = 446637024. Its totient is φ = 397010656.

The previous prime is 421823827. The next prime is 421823849. The reversal of 421823839 is 938328124.

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

It is not a de Polignac number, because 421823839 - 2¹⁷ = 421692767 is a prime.

It is a super-2 number, since 2×421823839² = 355870702297395842, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421823849) 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, 12406567 + ... + 12406600.

It is an arithmetic number, because the mean of its divisors is an integer number (111659256).

Almost surely, 2^421823839 is an apocalyptic number.

421823839 is a deficient number, since it is larger than the sum of its proper divisors (24813185).

421823839 is a wasteful number, since it uses less digits than its factorization.

421823839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24813184.

The product of its digits is 82944, while the sum is 40.

The square root of 421823839 is about 20538.3504449603. The cubic root of 421823839 is about 749.9696811447.

The spelling of 421823839 in words is "four hundred twenty-one million, eight hundred twenty-three thousand, eight hundred thirty-nine".