21033105997 has 2 divisors, whose sum is σ = 21033105998. Its totient is φ = 21033105996.

The previous prime is 21033105967. The next prime is 21033106007. The reversal of 21033105997 is 79950133012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12854797641 + 8178308356 = 113379^2 + 90434^2 .

It is a cyclic number.

It is not a de Polignac number, because 21033105997 - 2¹⁹ = 21032581709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21033105967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10516552998 + 10516552999.

It is an arithmetic number, because the mean of its divisors is an integer number (10516552999).

Almost surely, 2^21033105997 is an apocalyptic number.

It is an amenable number.

21033105997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21033105997 is an equidigital number, since it uses as much as digits as its factorization.

21033105997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51030, while the sum is 40.

The spelling of 21033105997 in words is "twenty-one billion, thirty-three million, one hundred five thousand, nine hundred ninety-seven".