20164381 has 2 divisors, whose sum is σ = 20164382. Its totient is φ = 20164380.

The previous prime is 20164379. The next prime is 20164393. The reversal of 20164381 is 18346102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15280281 + 4884100 = 3909^2 + 2210^2 .

It is a cyclic number.

It is not a de Polignac number, because 20164381 - 2¹ = 20164379 is a prime.

It is a super-2 number, since 2×20164381² = 813204522226322, which contains 22 as substring.

Together with 20164379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20164321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10082190 + 10082191.

It is an arithmetic number, because the mean of its divisors is an integer number (10082191).

Almost surely, 2^20164381 is an apocalyptic number.

It is an amenable number.

20164381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20164381 is an equidigital number, since it uses as much as digits as its factorization.

20164381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 20164381 is about 4490.4767007524. The cubic root of 20164381 is about 272.1833979771.

The spelling of 20164381 in words is "twenty million, one hundred sixty-four thousand, three hundred eighty-one".