221145684 has 12 divisors (see below), whose sum is σ = 516006624. Its totient is φ = 73715224.

The previous prime is 221145671. The next prime is 221145703. The reversal of 221145684 is 486541122.

It is a happy number.

221145684 is digitally balanced in base 2, 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 (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9214392 + ... + 9214415.

It is an arithmetic number, because the mean of its divisors is an integer number (43000552).

Almost surely, 2^221145684 is an apocalyptic number.

It is an amenable number.

221145684 is an abundant number, since it is smaller than the sum of its proper divisors (294860940).

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

221145684 is a wasteful number, since it uses less digits than its factorization.

221145684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18428814 (or 18428812 counting only the distinct ones).

The product of its digits is 15360, while the sum is 33.

The square root of 221145684 is about 14870.9678232454. The cubic root of 221145684 is about 604.7271806836.

It can be divided in two parts, 2211 and 45684, that added together give a triangular number (47895 = T₃₀₉).

The spelling of 221145684 in words is "two hundred twenty-one million, one hundred forty-five thousand, six hundred eighty-four".