1667549221 has 8 divisors (see below), whose sum is σ = 1797314904. Its totient is φ = 1537996800.

The previous prime is 1667549209. The next prime is 1667549267. The reversal of 1667549221 is 1229457661.

It can be written as a sum of positive squares in 4 ways, for example, as 106193025 + 1561356196 = 10305^2 + 39514^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1667549221 - 2¹⁷ = 1667418149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1667549201) by changing a digit.

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, 36880 + ... + 68521.

It is an arithmetic number, because the mean of its divisors is an integer number (224664363).

Almost surely, 2^1667549221 is an apocalyptic number.

It is an amenable number.

1667549221 is a deficient number, since it is larger than the sum of its proper divisors (129765683).

1667549221 is a wasteful number, since it uses less digits than its factorization.

1667549221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106631.

The product of its digits is 181440, while the sum is 43.

The square root of 1667549221 is about 40835.6366547652. The cubic root of 1667549221 is about 1185.8403413412.

The spelling of 1667549221 in words is "one billion, six hundred sixty-seven million, five hundred forty-nine thousand, two hundred twenty-one".