20015663 has 2 divisors, whose sum is σ = 20015664. Its totient is φ = 20015662.

The previous prime is 20015657. The next prime is 20015687. The reversal of 20015663 is 36651002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20015663 - 2¹⁰ = 20014639 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20015623) 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, 10007831 + 10007832.

It is an arithmetic number, because the mean of its divisors is an integer number (10007832).

Almost surely, 2^20015663 is an apocalyptic number.

20015663 is a deficient number, since it is larger than the sum of its proper divisors (1).

20015663 is an equidigital number, since it uses as much as digits as its factorization.

20015663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 20015663 is about 4473.8867889119. The cubic root of 20015663 is about 271.5126030414.

Adding to 20015663 its reverse (36651002), we get a palindrome (56666665).

The spelling of 20015663 in words is "twenty million, fifteen thousand, six hundred sixty-three".