21011009789998 has 4 divisors (see below), whose sum is σ = 31516514685000. Its totient is φ = 10505504894998.

The previous prime is 21011009789981. The next prime is 21011009789999. The reversal of 21011009789998 is 89998790011012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011009789999) 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 as a sum of consecutive naturals, namely, 5252752447498 + ... + 5252752447501.

It is an arithmetic number, because the mean of its divisors is an integer number (7879128671250).

Almost surely, 2^{21011009789998} is an apocalyptic number.

21011009789998 is a deficient number, since it is larger than the sum of its proper divisors (10505504895002).

21011009789998 is a wasteful number, since it uses less digits than its factorization.

21011009789998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10505504895001.

The product of its (nonzero) digits is 5878656, while the sum is 64.

The spelling of 21011009789998 in words is "twenty-one trillion, eleven billion, nine million, seven hundred eighty-nine thousand, nine hundred ninety-eight".