20105651 has 2 divisors, whose sum is σ = 20105652. Its totient is φ = 20105650.

The previous prime is 20105647. The next prime is 20105669. The reversal of 20105651 is 15650102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20105651 - 2² = 20105647 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20105681) 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, 10052825 + 10052826.

It is an arithmetic number, because the mean of its divisors is an integer number (10052826).

Almost surely, 2^20105651 is an apocalyptic number.

20105651 is a deficient number, since it is larger than the sum of its proper divisors (1).

20105651 is an equidigital number, since it uses as much as digits as its factorization.

20105651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 20105651 is about 4483.9325374051. The cubic root of 20105651 is about 271.9188907165.

Adding to 20105651 its reverse (15650102), we get a palindrome (35755753).

The spelling of 20105651 in words is "twenty million, one hundred five thousand, six hundred fifty-one".