20998633 has 2 divisors, whose sum is σ = 20998634. Its totient is φ = 20998632.

The previous prime is 20998619. The next prime is 20998673. The reversal of 20998633 is 33689902.

It is an a-pointer prime, because the next prime (20998673) can be obtained adding 20998633 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20313049 + 685584 = 4507^2 + 828^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20998633 is a prime.

It is not a weakly prime, because it can be changed into another prime (20998603) 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, 10499316 + 10499317.

It is an arithmetic number, because the mean of its divisors is an integer number (10499317).

Almost surely, 2^20998633 is an apocalyptic number.

It is an amenable number.

20998633 is a deficient number, since it is larger than the sum of its proper divisors (1).

20998633 is an equidigital number, since it uses as much as digits as its factorization.

20998633 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 20998633 is about 4582.4265406005. The cubic root of 20998633 is about 275.8864310807.

The spelling of 20998633 in words is "twenty million, nine hundred ninety-eight thousand, six hundred thirty-three".