21011100984 has 48 divisors (see below), whose sum is σ = 56925339120. Its totient is φ = 7001205120.

The previous prime is 21011100983. The next prime is 21011101009. The reversal of 21011100984 is 48900111012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011100983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 157324 + ... + 258404.

It is an arithmetic number, because the mean of its divisors is an integer number (1185944565).

Almost surely, 2^21011100984 is an apocalyptic number.

21011100984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21011100984 is an abundant number, since it is smaller than the sum of its proper divisors (35914238136).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21011100984 is a wasteful number, since it uses less digits than its factorization.

21011100984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103980 (or 103973 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 27.

Adding to 21011100984 its reverse (48900111012), we get a palindrome (69911211996).

The spelling of 21011100984 in words is "twenty-one billion, eleven million, one hundred thousand, nine hundred eighty-four".