20662381 has 2 divisors, whose sum is σ = 20662382. Its totient is φ = 20662380.

The previous prime is 20662357. The next prime is 20662393. The reversal of 20662381 is 18326602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15139881 + 5522500 = 3891^2 + 2350^2 .

It is a cyclic number.

It is not a de Polignac number, because 20662381 - 2⁹ = 20661869 is a prime.

It is a super-2 number, since 2×20662381² = 853867977178322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20662351) 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 as a sum of consecutive naturals, namely, 10331190 + 10331191.

It is an arithmetic number, because the mean of its divisors is an integer number (10331191).

Almost surely, 2^20662381 is an apocalyptic number.

It is an amenable number.

20662381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20662381 is an equidigital number, since it uses as much as digits as its factorization.

20662381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20662381 is about 4545.5891807333. The cubic root of 20662381 is about 274.4059064608.

Adding to 20662381 its reverse (18326602), we get a palindrome (38988983).

The spelling of 20662381 in words is "twenty million, six hundred sixty-two thousand, three hundred eighty-one".