164016821 has 8 divisors (see below), whose sum is σ = 167357880. Its totient is φ = 160684992.

The previous prime is 164016781. The next prime is 164016823. The reversal of 164016821 is 128610461.

It can be written as a sum of positive squares in 4 ways, for example, as 47679025 + 116337796 = 6905^2 + 10786^2 .

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 164016821 - 2⁶ = 164016757 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 (164016823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42071 + ... + 45803.

It is an arithmetic number, because the mean of its divisors is an integer number (20919735).

Almost surely, 2^164016821 is an apocalyptic number.

It is an amenable number.

164016821 is a deficient number, since it is larger than the sum of its proper divisors (3341059).

164016821 is an equidigital number, since it uses as much as digits as its factorization.

164016821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4615.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 164016821 is about 12806.9052077385. The cubic root of 164016821 is about 547.3890808989.

The spelling of 164016821 in words is "one hundred sixty-four million, sixteen thousand, eight hundred twenty-one".