221285628 has 48 divisors (see below), whose sum is σ = 603904000. Its totient is φ = 69879024.

The previous prime is 221285627. The next prime is 221285633. The reversal of 221285628 is 826582122.

221285628 is a `hidden beast` number, since 2 + 2 + 1 + 28 + 5 + 628 = 666.

221285628 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a junction number, because it is equal to n+sod(n) for n = 221285592 and 221285601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221285621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51868 + ... + 55971.

Almost surely, 2^221285628 is an apocalyptic number.

It is an amenable number.

221285628 is an abundant number, since it is smaller than the sum of its proper divisors (382618372).

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

221285628 is a wasteful number, since it uses less digits than its factorization.

221285628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107871 (or 107863 counting only the distinct ones).

The product of its digits is 30720, while the sum is 36.

The square root of 221285628 is about 14875.6723545526. The cubic root of 221285628 is about 604.8547136505.

The spelling of 221285628 in words is "two hundred twenty-one million, two hundred eighty-five thousand, six hundred twenty-eight".