21011121099 has 12 divisors (see below), whose sum is σ = 30351828312. Its totient is φ = 14006292000.

The previous prime is 21011121073. The next prime is 21011121127. The reversal of 21011121099 is 99012111012.

It is not a de Polignac number, because 21011121099 - 2⁸ = 21011120843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21011121059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34279 + ... + 207839.

It is an arithmetic number, because the mean of its divisors is an integer number (2529319026).

Almost surely, 2^21011121099 is an apocalyptic number.

21011121099 is a deficient number, since it is larger than the sum of its proper divisors (9340707213).

21011121099 is a wasteful number, since it uses less digits than its factorization.

21011121099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187018 (or 187015 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 27.

The spelling of 21011121099 in words is "twenty-one billion, eleven million, one hundred twenty-one thousand, ninety-nine".