228021520 has 40 divisors (see below), whose sum is σ = 530787456. Its totient is φ = 91099008.

The previous prime is 228021511. The next prime is 228021533. The reversal of 228021520 is 25120822.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×228021520² = 103987627166220800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 228021491 and 228021500.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 112839 + ... + 114841.

Almost surely, 2^228021520 is an apocalyptic number.

228021520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

228021520 is an abundant number, since it is smaller than the sum of its proper divisors (302765936).

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

228021520 is a wasteful number, since it uses less digits than its factorization.

228021520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3439 (or 3433 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 228021520 is about 15100.3814521356. The cubic root of 228021520 is about 610.9306943139.

The spelling of 228021520 in words is "two hundred twenty-eight million, twenty-one thousand, five hundred twenty".