21210687833 has 2 divisors, whose sum is σ = 21210687834. Its totient is φ = 21210687832.

The previous prime is 21210687803. The next prime is 21210687851. The reversal of 21210687833 is 33878601212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16489898569 + 4720789264 = 128413^2 + 68708^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210687833 - 2⁶ = 21210687769 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210687803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605343916 + 10605343917.

It is an arithmetic number, because the mean of its divisors is an integer number (10605343917).

Almost surely, 2^21210687833 is an apocalyptic number.

It is an amenable number.

21210687833 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210687833 is an equidigital number, since it uses as much as digits as its factorization.

21210687833 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96768, while the sum is 41.

The spelling of 21210687833 in words is "twenty-one billion, two hundred ten million, six hundred eighty-seven thousand, eight hundred thirty-three".