421640816 has 20 divisors (see below), whose sum is σ = 817342032. Its totient is φ = 210713856.

The previous prime is 421640809. The next prime is 421640819. The reversal of 421640816 is 618046124.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421640819) by changing a digit.

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, 33221 + ... + 44123.

Almost surely, 2^421640816 is an apocalyptic number.

It is an amenable number.

421640816 is a deficient number, since it is larger than the sum of its proper divisors (395701216).

421640816 is a wasteful number, since it uses less digits than its factorization.

421640816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13328 (or 13322 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 421640816 is about 20533.8943213410. The cubic root of 421640816 is about 749.8611986101.

The spelling of 421640816 in words is "four hundred twenty-one million, six hundred forty thousand, eight hundred sixteen".