221028804252 has 36 divisors (see below), whose sum is σ = 570599186976. Its totient is φ = 72108687360.

The previous prime is 221028804251. The next prime is 221028804257. The reversal of 221028804252 is 252408820122.

It is a happy number.

221028804252 is a `hidden beast` number, since 221 + 0 + 2 + 8 + 8 + 0 + 425 + 2 = 666.

221028804252 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221028804251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65314149 + ... + 65317532.

It is an arithmetic number, because the mean of its divisors is an integer number (15849977416).

Almost surely, 2^221028804252 is an apocalyptic number.

It is an amenable number.

221028804252 is an abundant number, since it is smaller than the sum of its proper divisors (349570382724).

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

221028804252 is a wasteful number, since it uses less digits than its factorization.

221028804252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130631738 (or 130631733 counting only the distinct ones).

The product of its (nonzero) digits is 40960, while the sum is 36.

The spelling of 221028804252 in words is "two hundred twenty-one billion, twenty-eight million, eight hundred four thousand, two hundred fifty-two".