21019019633 has 2 divisors, whose sum is σ = 21019019634. Its totient is φ = 21019019632.

The previous prime is 21019019603. The next prime is 21019019641. The reversal of 21019019633 is 33691091012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19068295744 + 1950723889 = 138088^2 + 44167^2 .

It is a cyclic number.

It is not a de Polignac number, because 21019019633 - 2⁸ = 21019019377 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21019019593 and 21019019602.

It is not a weakly prime, because it can be changed into another prime (21019019603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10509509816 + 10509509817.

It is an arithmetic number, because the mean of its divisors is an integer number (10509509817).

Almost surely, 2^21019019633 is an apocalyptic number.

It is an amenable number.

21019019633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21019019633 is an equidigital number, since it uses as much as digits as its factorization.

21019019633 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8748, while the sum is 35.

The spelling of 21019019633 in words is "twenty-one billion, nineteen million, nineteen thousand, six hundred thirty-three".