421394816 has 16 divisors (see below), whose sum is σ = 839497740. Its totient is φ = 210697344.

The previous prime is 421394801. The next prime is 421394821. The reversal of 421394816 is 618493124.

It is a tau number, because it is divible by the number of its divisors (16).

It is a self number, because there is not a number n which added to its sum of digits gives 421394816.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1645946 + ... + 1646201.

Almost surely, 2^421394816 is an apocalyptic number.

It is an amenable number.

421394816 is a deficient number, since it is larger than the sum of its proper divisors (418102924).

421394816 is an equidigital number, since it uses as much as digits as its factorization.

421394816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3292161 (or 3292149 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 421394816 is about 20527.9033512924. The cubic root of 421394816 is about 749.7153384893.

The spelling of 421394816 in words is "four hundred twenty-one million, three hundred ninety-four thousand, eight hundred sixteen".