21100123223129 has 2 divisors, whose sum is σ = 21100123223130. Its totient is φ = 21100123223128.

The previous prime is 21100123223117. The next prime is 21100123223183. The reversal of 21100123223129 is 92132232100112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11932520105104 + 9167603118025 = 3454348^2 + 3027805^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100123223129 - 2⁸ = 21100123222873 is a prime.

It is not a weakly prime, because it can be changed into another prime (21100123223929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550061611564 + 10550061611565.

It is an arithmetic number, because the mean of its divisors is an integer number (10550061611565).

Almost surely, 2^{21100123223129} is an apocalyptic number.

It is an amenable number.

21100123223129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100123223129 is an equidigital number, since it uses as much as digits as its factorization.

21100123223129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 29.

The spelling of 21100123223129 in words is "twenty-one trillion, one hundred billion, one hundred twenty-three million, two hundred twenty-three thousand, one hundred twenty-nine".