428733921 has 32 divisors (see below), whose sum is σ = 715511808. Its totient is φ = 221840640.

The previous prime is 428733919. The next prime is 428733959. The reversal of 428733921 is 129337824.

It is not a de Polignac number, because 428733921 - 2¹ = 428733919 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 428733921.

It is not an unprimeable number, because it can be changed into a prime (428733901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 57225 + ... + 64281.

It is an arithmetic number, because the mean of its divisors is an integer number (22359744).

Almost surely, 2^428733921 is an apocalyptic number.

It is an amenable number.

428733921 is a deficient number, since it is larger than the sum of its proper divisors (286777887).

428733921 is a wasteful number, since it uses less digits than its factorization.

428733921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7341.

The product of its digits is 72576, while the sum is 39.

The square root of 428733921 is about 20705.8909733438. The cubic root of 428733921 is about 754.0427152286.

The spelling of 428733921 in words is "four hundred twenty-eight million, seven hundred thirty-three thousand, nine hundred twenty-one".