20998963 has 2 divisors, whose sum is σ = 20998964. Its totient is φ = 20998962.

The previous prime is 20998951. The next prime is 20998969. The reversal of 20998963 is 36989902.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20998963 is a prime.

It is not a weakly prime, because it can be changed into another prime (20998969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10499481 + 10499482.

It is an arithmetic number, because the mean of its divisors is an integer number (10499482).

Almost surely, 2^20998963 is an apocalyptic number.

20998963 is a deficient number, since it is larger than the sum of its proper divisors (1).

20998963 is an equidigital number, since it uses as much as digits as its factorization.

20998963 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 46.

The square root of 20998963 is about 4582.4625475829. The cubic root of 20998963 is about 275.8878762866.

The spelling of 20998963 in words is "twenty million, nine hundred ninety-eight thousand, nine hundred sixty-three".