21123221009998 has 4 divisors (see below), whose sum is σ = 31684831515000. Its totient is φ = 10561610504998.

The previous prime is 21123221009977. The next prime is 21123221010029. The reversal of 21123221009998 is 89990012232112.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5280805252498 + ... + 5280805252501.

It is an arithmetic number, because the mean of its divisors is an integer number (7921207878750).

Almost surely, 2^{21123221009998} is an apocalyptic number.

21123221009998 is a deficient number, since it is larger than the sum of its proper divisors (10561610505002).

21123221009998 is a wasteful number, since it uses less digits than its factorization.

21123221009998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10561610505001.

The product of its (nonzero) digits is 279936, while the sum is 49.

The spelling of 21123221009998 in words is "twenty-one trillion, one hundred twenty-three billion, two hundred twenty-one million, nine thousand, nine hundred ninety-eight".