21000220999 has 2 divisors, whose sum is σ = 21000221000. Its totient is φ = 21000220998.

The previous prime is 21000220993. The next prime is 21000221003. The reversal of 21000220999 is 99902200012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000220999 - 2⁹ = 21000220487 is a prime.

It is a super-3 number, since 3×21000220999³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000220993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500110499 + 10500110500.

It is an arithmetic number, because the mean of its divisors is an integer number (10500110500).

Almost surely, 2^21000220999 is an apocalyptic number.

21000220999 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000220999 is an equidigital number, since it uses as much as digits as its factorization.

21000220999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 34.

The spelling of 21000220999 in words is "twenty-one billion, two hundred twenty thousand, nine hundred ninety-nine".