421439805 has 36 divisors (see below), whose sum is σ = 750882132. Its totient is φ = 218661120.

The previous prime is 421439797. The next prime is 421439813. The reversal of 421439805 is 508934124.

It is an interprime number because it is at equal distance from previous prime (421439797) and next prime (421439813).

It can be written as a sum of positive squares in 6 ways, for example, as 104101209 + 317338596 = 10203^2 + 17814^2 .

It is not a de Polignac number, because 421439805 - 2³ = 421439797 is a prime.

It is a super-2 number, since 2×421439805² = 355223018476876050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 421439805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 58185 + ... + 65025.

It is an arithmetic number, because the mean of its divisors is an integer number (20857837).

Almost surely, 2^421439805 is an apocalyptic number.

421439805 is a gapful number since it is divisible by the number (45) formed by its first and last digit.

It is an amenable number.

421439805 is a deficient number, since it is larger than the sum of its proper divisors (329442327).

421439805 is a wasteful number, since it uses less digits than its factorization.

421439805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6926 (or 6886 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 421439805 is about 20528.9991231916. Note that the first 3 decimals coincide. The cubic root of 421439805 is about 749.7420179372.

Adding to 421439805 its sum of digits (36), we get a square (421439841 = 20529²).

The spelling of 421439805 in words is "four hundred twenty-one million, four hundred thirty-nine thousand, eight hundred five".