421556845 has 4 divisors (see below), whose sum is σ = 505868220. Its totient is φ = 337245472.

The previous prime is 421556833. The next prime is 421556867. The reversal of 421556845 is 548655124.

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

It can be written as a sum of positive squares in 2 ways, for example, as 312688489 + 108868356 = 17683^2 + 10434^2 .

It is a cyclic number.

It is not a de Polignac number, because 421556845 - 2⁵ = 421556813 is a prime.

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 junction number, because it is equal to n+sod(n) for n = 421556798 and 421556807.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42155680 + ... + 42155689.

It is an arithmetic number, because the mean of its divisors is an integer number (126467055).

Almost surely, 2^421556845 is an apocalyptic number.

It is an amenable number.

421556845 is a deficient number, since it is larger than the sum of its proper divisors (84311375).

421556845 is an equidigital number, since it uses as much as digits as its factorization.

421556845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84311374.

The product of its digits is 192000, while the sum is 40.

The square root of 421556845 is about 20531.8495270153. The cubic root of 421556845 is about 749.8114162893.

The spelling of 421556845 in words is "four hundred twenty-one million, five hundred fifty-six thousand, eight hundred forty-five".