20646137 has 2 divisors, whose sum is σ = 20646138. Its totient is φ = 20646136.

The previous prime is 20646107. The next prime is 20646151. The reversal of 20646137 is 73164602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15713296 + 4932841 = 3964^2 + 2221^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20646137 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20646107) 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, 10323068 + 10323069.

It is an arithmetic number, because the mean of its divisors is an integer number (10323069).

Almost surely, 2^20646137 is an apocalyptic number.

It is an amenable number.

20646137 is a deficient number, since it is larger than the sum of its proper divisors (1).

20646137 is an equidigital number, since it uses as much as digits as its factorization.

20646137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 20646137 is about 4543.8020423430. The cubic root of 20646137 is about 274.3339783491. Note that the first 3 decimals are identical.

The spelling of 20646137 in words is "twenty million, six hundred forty-six thousand, one hundred thirty-seven".