164366021 has 4 divisors (see below), whose sum is σ = 164854092. Its totient is φ = 163877952.

The previous prime is 164366011. The next prime is 164366039. The reversal of 164366021 is 120663461.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 120143521 + 44222500 = 10961^2 + 6650^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-164366021 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 (164366011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243530 + ... + 244203.

It is an arithmetic number, because the mean of its divisors is an integer number (41213523).

Almost surely, 2^164366021 is an apocalyptic number.

It is an amenable number.

164366021 is a deficient number, since it is larger than the sum of its proper divisors (488071).

164366021 is an equidigital number, since it uses as much as digits as its factorization.

164366021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488070.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 164366021 is about 12820.5312292432. The cubic root of 164366021 is about 547.7772784252. Note that the first 3 decimals are identical.

The spelling of 164366021 in words is "one hundred sixty-four million, three hundred sixty-six thousand, twenty-one".