21021200122099 has 4 divisors (see below), whose sum is σ = 21021209443936. Its totient is φ = 21021190800264.

The previous prime is 21021200122079. The next prime is 21021200122121. The reversal of 21021200122099 is 99022100212012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21021200122099 - 2⁹ = 21021200121587 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21021200122099.

It is not an unprimeable number, because it can be changed into a prime (21021200122079) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1072822 + ... + 6572164.

It is an arithmetic number, because the mean of its divisors is an integer number (5255302360984).

Almost surely, 2^{21021200122099} is an apocalyptic number.

21021200122099 is a deficient number, since it is larger than the sum of its proper divisors (9321837).

21021200122099 is an equidigital number, since it uses as much as digits as its factorization.

21021200122099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9321836.

The product of its (nonzero) digits is 2592, while the sum is 31.

The spelling of 21021200122099 in words is "twenty-one trillion, twenty-one billion, two hundred million, one hundred twenty-two thousand, ninety-nine".