20164649 has 2 divisors, whose sum is σ = 20164650. Its totient is φ = 20164648.

The previous prime is 20164631. The next prime is 20164733. The reversal of 20164649 is 94646102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 94249 = 4480^2 + 307^2 .

It is a cyclic number.

It is not a de Polignac number, because 20164649 - 2⁸ = 20164393 is a prime.

It is a super-3 number, since 3×20164649³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20164049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10082324 + 10082325.

It is an arithmetic number, because the mean of its divisors is an integer number (10082325).

Almost surely, 2^20164649 is an apocalyptic number.

It is an amenable number.

20164649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20164649 is an equidigital number, since it uses as much as digits as its factorization.

20164649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 20164649 is about 4490.5065415830. The cubic root of 20164649 is about 272.1846038134.

The spelling of 20164649 in words is "twenty million, one hundred sixty-four thousand, six hundred forty-nine".