21100123451099 has 48 divisors (see below), whose sum is σ = 27327392491776. Its totient is φ = 15826725129600.

The previous prime is 21100123451087. The next prime is 21100123451131. The reversal of 21100123451099 is 99015432100112.

It is not a de Polignac number, because 21100123451099 - 2⁴ = 21100123451083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21100123451059) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20942369 + ... + 21926765.

It is an arithmetic number, because the mean of its divisors is an integer number (569320676912).

Almost surely, 2^{21100123451099} is an apocalyptic number.

21100123451099 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21100123451099 is a deficient number, since it is larger than the sum of its proper divisors (6227269040677).

21100123451099 is a wasteful number, since it uses less digits than its factorization.

21100123451099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984804 (or 984775 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 38.

The spelling of 21100123451099 in words is "twenty-one trillion, one hundred billion, one hundred twenty-three million, four hundred fifty-one thousand, ninety-nine".