428172721920 has 576 divisors, whose sum is σ = 1562261904000. Its totient is φ = 110981283840.

The previous prime is 428172721829. The next prime is 428172721937. The reversal of 428172721920 is 29127271824.

428172721920 is a `hidden beast` number, since 428 + 1 + 7 + 2 + 7 + 219 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 636214704 + ... + 636215376.

It is an arithmetic number, because the mean of its divisors is an integer number (2712260250).

Almost surely, 2^428172721920 is an apocalyptic number.

428172721920 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 428172721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (781130952000).

428172721920 is an abundant number, since it is smaller than the sum of its proper divisors (1134089182080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

428172721920 is a wasteful number, since it uses less digits than its factorization.

428172721920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1193 (or 1173 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The spelling of 428172721920 in words is "four hundred twenty-eight billion, one hundred seventy-two million, seven hundred twenty-one thousand, nine hundred twenty".