21020001221099 has 2 divisors, whose sum is σ = 21020001221100. Its totient is φ = 21020001221098.

The previous prime is 21020001221081. The next prime is 21020001221123. The reversal of 21020001221099 is 99012210002012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21020001221099 - 2⁸ = 21020001220843 is a prime.

It is not a weakly prime, because it can be changed into another prime (21020001221059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510000610549 + 10510000610550.

It is an arithmetic number, because the mean of its divisors is an integer number (10510000610550).

Almost surely, 2^{21020001221099} is an apocalyptic number.

21020001221099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020001221099 is an equidigital number, since it uses as much as digits as its factorization.

21020001221099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 29.

The spelling of 21020001221099 in words is "twenty-one trillion, twenty billion, one million, two hundred twenty-one thousand, ninety-nine".