421728868 has 24 divisors (see below), whose sum is σ = 818322624. Its totient is φ = 188551200.

The previous prime is 421728859. The next prime is 421728871. The reversal of 421728868 is 868827124.

It is a happy number.

It is a super-2 number, since 2×421728868² = 355710476209122848, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75880 + ... + 81247.

It is an arithmetic number, because the mean of its divisors is an integer number (34096776).

Almost surely, 2^421728868 is an apocalyptic number.

It is an amenable number.

421728868 is a deficient number, since it is larger than the sum of its proper divisors (396593756).

421728868 is a wasteful number, since it uses less digits than its factorization.

421728868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157203 (or 157201 counting only the distinct ones).

The product of its digits is 344064, while the sum is 46.

The square root of 421728868 is about 20536.0382742144. The cubic root of 421728868 is about 749.9133932587.

It can be divided in two parts, 42172 and 8868, that added together give a triangular number (51040 = T₃₁₉).

The spelling of 421728868 in words is "four hundred twenty-one million, seven hundred twenty-eight thousand, eight hundred sixty-eight".