21111010984 has 64 divisors (see below), whose sum is σ = 46907942400. Its totient is φ = 8715033600.

The previous prime is 21111010981. The next prime is 21111011021. The reversal of 21111010984 is 48901011112.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (21111010981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 684864 + ... + 715024.

It is an arithmetic number, because the mean of its divisors is an integer number (732936600).

Almost surely, 2^21111010984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111010984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23453971200).

21111010984 is an abundant number, since it is smaller than the sum of its proper divisors (25796931416).

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

21111010984 is a wasteful number, since it uses less digits than its factorization.

21111010984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30634 (or 30630 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 28.

The spelling of 21111010984 in words is "twenty-one billion, one hundred eleven million, ten thousand, nine hundred eighty-four".